| Monster | Size | Type | Alignment | CR | Source | Page | Terrain |
| Ammut | Large | Celestial | Neutral | 9 | CC | 15 | Badlands, Desert |
| Animated Offal | Huge | Ooze | Unaligned | 9 | ToB3 | 38 | Any |
| Anzu | Large | Monstrosity | Neutral | 9 | ToB2 | 26 | Desert, Grassland, Mountains |
| Arcane Scavenger | Large | Construct | Neutral | 9 | ToB3 | 41 | Badlands |
| Archon, Ursan | Large | Celestial | Chaotic Good | 9 | ToB3 | 43 | Any |
| Ash Phoenix | Large | Undead | Neutral Evil | 9 | ToB2 | 28 | Any |
| Aurora Horribilis | Large | Aberration | Chaotic Neutral | 9 | ToB2 | 34 | Arctic |
| Bukavac | Large | Monstrosity | Neutral Evil | 9 | ToB1 | 47 | Forests, Swamp |
| Chaos Creeper | Medium | Plant | Chaotic Neutral | 9 | ToB3 | 80 | Hills |
| Clockwork Scorpion | Large | Construct | Unaligned | 9 | ToB3 | 89 | Urban |
| Coastline Reaper | Large | Monstrosity | Unaligned | 9 | ToB3 | 92 | Coastal, Underwater |
| Cultist, Psychophant | Medium | Humanoid | Any Non-Good | 9 | ToB3 | 405 | Any |
| Demon, Alnaar | Large | Fiend | Chaotic Evil | 9 | CC | 82 | Planar |
| Demon, Fulad-Zereh | Huge | Fiend | Chaotic Evil | 9 | CC | 85 | Planar |
| Demon, Malakbel | Medium | Fiend | Chaotic Evil | 9 | ToB1 | 78 | Any |
| Demon, Yek Alpha | Medium | Fiend | Chaotic Evil | 9 | CC | 95 | Any |
| Devilbound Gnomish Prince | Small | Humanoid | Any Evil | 9 | ToB1 | 420 | Any |
| Dimensional Shambler | Large | Aberration | Neutral Evil | 9 | ToB2 | 107 | Planar |
| Dragon, Flame, Young | Large | Dragon | Chaotic Evil | 9 | ToB1 | 130 | Mountains, Ruins, Underground |
| Dragon, Sea, Young | Large | Dragon | Neutral Evil | 9 | ToB1 | 136 | Mountains, Underwater |
| Dragon, Void, Young | Large | Dragon | Chaotic Neutral | 9 | ToB1 | 140 | Mountains |
| Dragon, Wasteland, Young | Large | Dragon | Chaotic Evil | 9 | CC | 118 | Badlands, Hills |
| Drake, Deep | Large | Dragon | Chaotic Evil | 9 | ToB1 | 152 | Ruins, Underground |
| Drake, Reef | Huge | Dragon | Neutral Evil | 9 | ToB3 | 154 | Coastal, Underwater |
| Drake, Spider | Large | Dragon | Lawful Evil | 9 | CC | 133 | Underground |
| Eater of Dust (Yakat-shi) | Medium | Aberration | Neutral Evil | 9 | ToB1 | 164 | Any |
| Elf, Shadow Fey Ambassador | Medium | Humanoid | Lawful Evil | 9 | CC | 145 | Underground, Urban |
| Flame-Scourged Scion | Huge | Aberration | Chaotic Evil | 9 | CC | 159 | Badlands, Forest |
| Fulminar | Large | Elemental | Neutral | 9 | CC | 165 | Grassland, Hills, Mountains |
| Garmvvolf | Huge | Monstrosity | Unaligned | 9 | ToB3 | 194 | Mountains, Underground |
| Genie, Al-Aeshma | Large | Elemental | Chaotic Evil | 9 | ToB1 | 211 | Any |
| Ghoul, Darakhul Captain | Medium | Undead | Lawful Evil | 9 | ToB2 | 166 | Underground, Urban |
| Ghoul, Darakhul High Priestess | Medium | Undead | Neutral Evil | 9 | CC | 172 | Underground |
| Giant, Desert | Huge | Giant | Neutral | 9 | ToB1 | 222 | Desert |
| Giant, Hellfire | Huge | Giant | Neutral Good | 9 | ToB3 | 203 | Mountains, Planar |
| Giant, Thin | Huge | Giant | Chaotic Evil | 9 | ToB2 | 175 | Underground, Urban |
| Golem, Alchemical | Large | Construct | Unaligned | 9 | CC | 192 | Any |
| Golem, Lotus | Large | Construct | Unaligned | 9 | CC | 202 | Any |
| Gulper Behemoth | Gargantuan | Monstrosity | Unaligned | 9 | ToB2 | 190 | Underwater |
| Hag, Brine | Medium | Fey | Lawful Evil | 9 | ToB3 | 225 | Coastal, Underwater |
| Hag, Wood | Medium | Fey | Neutral Evil | 9 | ToB3 | 228 | Forest, Hills, Mountains, Swamp |
| Horakh | Medium | Monstrosity | Neutral | 9 | ToB1 | 250 | Desert, Grassland, Ruins, Underground |
| Huli Jing | Medium | Fey | Neutral | 9 | ToB2 | 204 | Farmland, Urban |
| Incandescent One | Medium | Celestial | Chaotic Good | 9 | ToB3 | 244 | Coastal, Underwater |
| Infested Duelist | Medium | Humanoid | Chaotic Neutral | 9 | ToB3 | 409 | Any |
| Jinmenju | Huge | Plant | Chaotic Neutral | 9 | CC | 232 | Forest |
| Kami, Sasori Fukurōwashi | Medium | Fey | Neutral Good | 9 | ToB2 | 224 | Any, Planar |
| Keelbreaker Crab | Huge | Monstrosity | Unaligned | 9 | ToB2 | 226 | Coastal, Underwater |
| Khargi | Huge | Fiend | Neutral Evil | 9 | ToB3 | 251 | Badlands |
| Kirikari | Huge | Monstrosity | Unaligned | 9 | ToB2 | 230 | Swamp |
| Kobold War Machine | Large | Construct | Unaligned | 9 | ToB2 | 233 | Any |
| Krake Spawn | Huge | Monstrosity | Neutral Evil | 9 | ToB1 | 269 | Underwater |
| Külmking | Large | Undead | Chaotic Evil | 9 | CC | 244 | Forest, Grassland |
| Lich, Hierophant | Medium | Undead | Any Evil | 9 | CC | 252 | Any |
| Mantik | Huge | Monstrosity | Lawful Evil | 9 | CC | 262 | Badlands |
| Murgrik | Large | Aberration | Chaotic Evil | 9 | ToB2 | 263 | Swamp |
| Myrmex, Speaker | Large | Elemental | Neutral Good | 9 | ToB3 | 284 | Planar, Underground |
| Mytholabe | Large | Construct | Unaligned | 9 | CC | 271 | Any |
| Necrotech, Bonecage Constrictor | Huge | Undead | Neutral Evil | 9 | ToB3 | 287 | Any |
| Nharyth | Huge | Aberration | Chaotic Evil | 9 | ToB2 | 269 | Underground |
| Oasis Keeper | Huge | Monstrosity | Unaligned | 9 | ToB2 | 273 | Desert, Underwater |
| Oozasis | Gargantuan | Ooze | Unaligned | 9 | ToB1 | 310 | Desert, Swamp |
| Ooze, Sinoper | Medium | Ooze | Unaligned | 9 | ToB3 | 310 | Urban |
| Pelagic Blush Worm | Gargantuan | Monstrosity | Unaligned | 9 | ToB3 | 313 | Underwater |
| Pine Doom | Huge | Plant | Neutral | 9 | ToB2 | 295 | Arctic, Forest |
| Plague Spirit | Medium | Fey | Unaligned | 9 | ToB2 | 296 | Any |
| Rakshasa, Slayer | Medium | Fiend | Lawful Evil | 9 | ToB3 | 330 | Urban |
| Righteous Sentinel | Large | Construct | Lawful Good | 9 | ToB2 | 307 | Urban |
| Shadow River Lord | Medium | Undead | Neutral Evil | 9 | CC | 327 | Forest, Underwater |
| Shriekbat | Huge | Monstrosity | Unaligned | 9 | ToB2 | 325 | Underground |
| Shukankor | Huge | Aberration | Chaotic Evil | 9 | ToB2 | 326 | Badlands, Desert, Grassland |
| Skeleton, Monarch | Medium | Undead | Neutral Evil | 9 | CC | 341 | Any |
| Skeleton, Vine Troll | Large | Plant | Unaligned | 9 | ToB1 | 351 | Any |
| Spider, Ghostwalk | Large | Monstrosity | Neutral Evil | 9 | ToB1 | 361 | Badlands, Forests |
| Star-Nosed Diopsid | Large | Aberration | Lawful Evil | 9 | ToB3 | 355 | Forest, Grassland |
| Stargazer | Huge | Monstrosity | Unaligned | 9 | ToB3 | 354 | Badlands, Coastal, Desert |
| Thornheart Guardian | Large | Construct | Lawful Evil | 9 | ToB2 | 346 | Forest, Swamp |
| Truant Devourer | Medium | Undead | Any | 9 | ToB3 | 378 | Planar |
| Ushabti | Large | Construct | Unaligned | 9 | ToB1 | 394 | Ruins, Underground |
| Warmth Thief | Tiny | Fey | Neutral Evil | 9 | ToB2 | 366 | Arctic |
| Wickerman | Huge | Construct | Neutral Evil | 9 | CC | 380 | Forest |
| Wraith Bear | Large | Undead | Chaotic Evil | 9 | ToB2 | 375 | Forest |
| Alazai | Large | Elemental | Chaotic Neutral | 10 | ToB3 | 15 | Badlands, Desert |
| Algorith | Medium | Construct | Lawful Evil | 10 | ToB1 | 14 | Any |
| Animal Lord, Toad King | Medium | Fey | Neutral | 10 | ToB2 | 22 | Swamp |
| Aphasian Abomination | Large | Construct | Unaligned | 10 | ToB3 | 39 | Badlands |
| Belu | Huge | Giant | Chaotic Good | 10 | ToB3 | 55 | Forest, Swamp |
| Blood Flurry | Medium | Aberration | Neutral Evil | 10 | ToB3 | 63 | Arctic |
| Bone Swarm | Large | Undead | Chaotic Evil | 10 | ToB1 | 41 | Any |
| Catonoctrix | Large | Aberration | Neutral Evil | 10 | ToB3 | 75 | Badlands, Planar |
| Colláis | Large | Monstrosity | Neutral | 10 | ToB2 | 69 | Forest |
| Conjoined Queen | Large | Monstrosity | Chaotic Neutral | 10 | ToB2 | 70 | Underground, Urban |
| Demon, Rubezahl | Medium | Fiend | Chaotic Evil | 10 | ToB1 | 80 | Any |
| Demon, Spawn of Hriggala | Huge | Fiend | Chaotic Evil | 10 | ToB2 | 89 | Planar |
| Despair and Anger | Large | Celestial | Neutral Evil | 10 | ToB3 | 116 | Planar |
| Devil, Automata | Large | Fiend | Lawful Evil | 10 | ToB1 | 102 | Any |
| Dragon, Blue, Zombie, Young | Large | Undead | Neutral Evil | 10 | ToB2 | 385 | Any |
| Drudge Pitcher | Huge | Plant | Unaligned | 10 | ToB3 | 161 | Forest |
| Elf, Alchemist Archer | Medium | Humanoid | Any | 10 | CC | 141 | Any |
| Fabricator | Large | Construct | Neutral | 10 | ToB2 | 138 | Any |
| Fear Smith (Fiarsídhe) | Medium | Fey | Chaotic Neutral | 10 | ToB1 | 181 | Any |
| Field Commander | Medium | Humanoid | Any | 10 | ToB3 | 406 | Any |
| Forgotten Regent | Medium | Undead | Lawful Neutral | 10 | ToB3 | 187 | Arctic, Mountains |
| Frostjack | Medium | Fey | Neutral Evil | 10 | ToB3 | 189 | Arctic |
| Ghost Knight Templar | Medium | Undead | Lawful Evil | 10 | ToB3 | 196 | Farmland, Urban |
| Giant, Cave | Huge | Giant | Chaotic Evil | 10 | CC | 182 | Underground |
| Golem, Altar Flame | Large | Construct | Neutral | 10 | CC | 193 | Urban |
| Golem, Doom | Large | Construct | Unaligned | 10 | CC | 197 | Any |
| Golem, Dragonflesh | Large | Construct | Unaligned | 10 | ToB2 | 180 | Any |
| Golem, Salt | Large | Construct | Unaligned | 10 | ToB1 | 235 | Desert, Underwater |
| Grave Behemoth | Huge | Undead | Neutral Evil | 10 | CC | 208 | Any |
| Hundun | Large | Celestial | Chaotic Good | 10 | ToB1 | 253 | Any |
| Hydra, Chameleon | Huge | Monstrosity | Unaligned | 10 | ToB2 | 208 | Forest |
| Incinis | Large | Elemental | Neutral Evil | 10 | CC | 226 | Mountains |
| Kelp Eel | Huge | Plant | Unaligned | 10 | ToB2 | 227 | Underwater |
| Kobold, Empyrean | Small | Celestial | Neutral | 10 | ToB3 | 253 | Any |
| Kobold, Leviathan Hunter | Medium | Humanoid | Chaotic Neutral | 10 | ToB3 | 255 | Coastal, Underwater |
| Kobold, Planes Hunter | Small | Humanoid | Neutral | 10 | ToB3 | 256 | Planar |
| Lamassu | Large | Celestial | Lawful Good | 10 | CC | 247 | Badlands, Desert |
| Luck Leech | Medium | Fey | Neutral Evil | 10 | ToB2 | 241 | Urban |
| Malleable, Major | Huge | Aberration | Chaotic Evil | 10 | ToB2 | 254 | Any |
| Nightgaunt | Large | Aberration | Lawful Evil | 10 | CC | 277 | Planar |
| Nyctli Swarm | Large | Fey | Chaotic Evil | 10 | ToB2 | 271 | Forest |
| Oaken Sentinel | Huge | Plant | Unaligned | 10 | ToB3 | 293 | Forest |
| Ooze, Foxfire | Large | Ooze | Unaligned | 10 | CC | 283 | Forest, Grassland, Swamp |
| Ooze, Shoal | Gargantuan | Ooze | Unaligned | 10 | ToB3 | 308 | Underwater |
| Peat Mammoth | Huge | Plant | Neutral | 10 | ToB2 | 293 | Swamp |
| Pumpkin King | Huge | Fey | Chaotic Neutral | 10 | ToB2 | 298 | Farmland, Forest |
| Qiqirn, Tormented | Large | Fiend | Chaotic Evil | 10 | ToB2 | 302 | Arctic |
| Runeswarm | Large | Construct | Unaligned | 10 | ToB2 | 310 | Any, Arctic |
| Sathaq Worm | Huge | Elemental | Neutral Evil | 10 | ToB1 | 337 | Desert, Ruins, Underground, Swamp |
| Scarab, Suncatcher | Gargantuan | Beast | Unaligned | 10 | ToB3 | 338 | Desert, Underground |
| Theullai | Huge | Elemental | Chaotic Neutral | 10 | ToB1 | 379 | Any |
| Underworld Sentinel | Huge | Undead | Neutral | 10 | ToB3 | 381 | Underground, Urban |
| Vampire, Patrician | Medium | Undead | Lawful Evil | 10 | CC | 365 | Urban |
| Void Knight | Medium | Construct | Lawful Evil | 10 | ToB3 | 386 | Any |
| Wandering Haze | Gargantuan | Ooze | Unaligned | 10 | ToB3 | 389 | Mountains |
| Abominable Beauty | Medium | Fey | Neutral Evil | 11 | ToB1 | 11 | Any |
| Angel, Pelagic Deva | Medium | Celestial | Neutral Good | 11 | ToB3 | 27 | Planar, Underwater |
| Baba Yaga's Horsemen | Medium | Fey | Lawful Neutral | 11 | ToB1 | 29 | Any |
| Black Crier | Medium | Undead | Neutral | 11 | ToB2 | 42 | Farmland, Urban |
| Black Shuck | Large | Fiend | Chaotic Evil | 11 | ToB3 | 59 | Farmland |
| Broodmother of Leng | Huge | Aberration | Chaotic Evil | 11 | ToB2 | 52 | Planar |
| Buraq | Medium | Celestial | Lawful Good | 11 | ToB1 | 48 | Any |
| Clockwork Tactician | Medium | Construct | Lawful Neutral | 11 | ToB3 | 90 | Urban |
| Corpse Mound | Huge | Undead | Neutral Evil | 11 | ToB1 | 69 | Any |
| Demon, Berstuc | Large | Fiend | Chaotic Evil | 11 | ToB1 | 76 | Any |
| Demon, Leech | Large | Fiend | Chaotic Evil | 11 | ToB3 | 110 | Swamp |
| Devil, Koralk (Harvester Devil) | Large | Fiend | Lawful Evil | 11 | ToB1 | 108 | Any |
| Dinosaur, Thundercall Hadrosaur | Huge | Monstrosity | Unaligned | 11 | ToB3 | 129 | Farmland, Grassland, Swamp |
| Dragon, Ghost | Large | Undead | Any | 11 | CC | 170 | Any |
| Dragon, Imperial, Young | Large | Dragon | Neutral | 11 | ToB2 | 117 | Coastal, Underwater |
| Dragon, Sand Young | Large | Dragon | Neutral Evil | 11 | ToB3 | 147 | Badlands, Desert |
| Dragonborn, Ouroban | Medium | Humanoid | Neutral Evil | 11 | CC | 125 | Any |
| Drake, Crater | Small | Dragon | Neutral Evil | 11 | ToB2 | 120 | Badlands |
| Drake, Riptide | Large | Dragon | Lawful Evil | 11 | ToB3 | 155 | Coastal, Underwater |
| Dryad, Mountain | Huge | Fey | Neutral | 11 | ToB2 | 130 | Hills, Mountains |
| Dullahan | Large | Fey | Unaligned | 11 | ToB1 | 161 | Any |
| Ecstatic Bloom | Huge | Celestial | Neutral Good | 11 | CC | 303 | Any |
| Elf, Shadow Fey Poisoner | Medium | Humanoid | Neutral | 11 | CC | 148 | Underground, Urban |
| Fey Lady, Mother Moth | Medium | Fey | Neutral | 11 | ToB3 | 179 | Forest, Planar |
| Flying Polyp | Huge | Aberration | Chaotic Evil | 11 | CC | 162 | Planar |
| Giant, Void | Huge | Giant | Chaotic Neutral | 11 | CC | 187 | Mountains, Planar |
| Glacial Crawler | Huge | Aberration | Unaligned | 11 | ToB3 | 209 | Arctic, Coastal, Underwater |
| Goblin Siege Engine | Huge | Construct | Unaligned | 11 | ToB3 | 211 | Any |
| Golem, Eye | Large | Construct | Unaligned | 11 | ToB1 | 233 | Any |
| Grim Jester | Medium | Undead | Chaotic Evil | 11 | ToB1 | 240 | Any |
| Grivid | Large | Aberration | Neutral | 11 | ToB3 | 221 | Badlands, Grassland |
| Hag, Blood | Medium | Fey | Chaotic Evil | 11 | ToB1 | 242 | Any |
| Herald of Slaughter | Large | Fiend | Chaotic Evil | 11 | ToB2 | 198 | Urban |
| Herald of the Void | Large | Fiend | Chaotic Evil | 11 | ToB2 | 199 | Planar |
| Herald of Undeath | Large | Undead | Lawful Evil | 11 | CC | 219 | Farmland, Urban |
| Ichneumon | Large | Monstrosity | Unaligned | 11 | CC | 224 | Hills, Mountains, Underground |
| Imperator | Huge | Monstrosity | Neutral | 11 | ToB3 | 243 | Arctic, Underwater |
| Kobold, Ghost Hunter | Small | Humanoid | Neutral | 11 | ToB3 | 254 | Any |
| Mouse King | Small | Fey | Neutral | 11 | CC | 29 | Urban |
| Naina | Large | Dragon | Lawful Evil | 11 | ToB1 | 302 | Any |
| Thorned Sulfurlord | Huge | Fiend | Chaotic Evil | 11 | CC | 306 | Any |
| Valkyrie | Medium | Celestial | Neutral | 11 | ToB1 | 396 | Any |
| Vampiric Knight | Medium | Undead | Neutral Evil | 11 | CC | 369 | Any |
| Vesiculosa | Gargantuan | Plant | Unaligned | 11 | ToB1 | 399 | Badlands, Desert |
| Voidling | Large | Aberration | Chaotic Evil | 11 | ToB1 | 404 | Any |
| Wendigo | Medium | Monstrosity | Chaotic Evil | 11 | CC | 377 | Arctic, Farmland, Mountains |
| Xing Tian | Huge | Giant | Neutral | 11 | ToB2 | 376 | Forest, Hills |
| Ychen Bannog | Gargantuan | Beast | Unaligned | 11 | ToB1 | 413 | Forests, Hills, Mountains |
| Aboleth, Nihileth | Large | Undead | Chaotic Evil | 12 | ToB1 | 8 | Any |
| Akkorokamui | Gargantuan | Celestial | Chaotic Good | 12 | ToB3 | 11 | Coastal, Underwater |
| Angel, Angelic Enforcer | Large | Celestial | Lawful Good | 12 | ToB2 | 17 | Planar |
| Boneshard Wraith | Medium | Undead | Neutral Evil | 12 | ToB2 | 46 | Badlands |
| Chronomatic Enhancer | Large | Construct | Unaligned | 12 | ToB2 | 64 | Urban |
| Demon Lord, Akyishigal, of Cockroaches | Large | Fiend | Chaotic Evil | 12 | ToB1 | 82 | Any |
| Demon, Culicoid | Large | Fiend | Chaotic Evil | 12 | ToB2 | 94 | Planar, Swamp |
| Demon, Maha | Medium | Fiend | Chaotic Evil | 12 | ToB3 | 111 | Arctic |
| Derendian Moth Abomination | Huge | Monstrosity | Neutral Evil | 12 | ToB2 | 96 | Forest |
| Devil, Chort | Medium | Fiend | Lawful Evil | 12 | ToB1 | 104 | Any |
| Devil, Maelstrom | Large | Fiend | Lawful Evil | 12 | ToB3 | 122 | Coastal, Planar, Underwater |
| Devouring Angel | Large | Aberration | Neutral | 12 | ToB3 | 125 | Planar |
| Dragon Eel | Huge | Dragon | Neutral | 12 | ToB1 | 146 | Ruins, Underground, Underwater |
| Fey Lord, Bear King | Medium | Fey | Lawful Neutral | 12 | ToB1 | 186 | Forests, Hills |
| Fey Lord, Reynard | Medium | Fey | Chaotic Neutral | 12 | CC | 156 | Forest |
| First Servant | Medium | Humanoid | Any | 12 | ToB3 | 407 | Any |
| Flutterflesh | Large | Undead | Chaotic Evil | 12 | ToB1 | 203 | Any |
| Galidroo | Huge | Monstrosity | Neutral Evil | 12 | ToB2 | 161 | Badlands, Underground |
| Ghoul, Bonepowder | Small | Undead | Neutral Evil | 12 | ToB1 | 214 | Ruins, Underground |
| Giant, Lantern | Huge | Giant | Neutral | 12 | ToB3 | 204 | Underwater |
| Glacier Behemoth | Huge | Beast | Unaligned | 12 | ToB2 | 177 | Arctic |
| Golem, Hoard | Huge | Construct | Unaligned | 12 | ToB1 | 234 | Any |
| Gug | Huge | Giant | Neutral Evil | 12 | ToB1 | 241 | Ruins, Underground |
| Herald of Blood | Huge | Fiend | Neutral Evil | 12 | ToB1 | 248 | Any |
| Herald of Fire | Large | Dragon | Lawful Evil | 12 | CC | 215 | Any |
| Horned Serpent | Large | Monstrosity | Unaligned | 12 | CC | 220 | Forest, Grassland, Swamp |
| Illhveli, Kembingur | Gargantuan | Monstrosity | Chaotic Evil | 12 | ToB2 | 211 | Underwater |
| Infernal Swarm | Huge | Fiend | Lawful Evil | 12 | ToB2 | 215 | Planar |
| Lich, Virtuoso | Medium | Undead | Any Evil | 12 | ToB2 | 237 | Urban |
| Lord of Vultures | Large | Fey | Neutral Good | 12 | CC | 26 | Mountains |
| Mavka | Medium | Undead | Chaotic Evil | 12 | ToB1 | 286 | Any |
| Necrotech, Death Barque | Gargantuan | Undead | Neutral Evil | 12 | ToB2 | 268 | Underwater |
| Ooze, Scintillating | Large | Ooze | Neutral | 12 | ToB3 | 307 | Farmland, Underground, Urban |
| Queen of Serpents | Medium | Fey | Lawful Neutral | 12 | CC | 34 | Mountains |
| Satarre, Lord of the Satarre | Large | Fiend | Neutral Evil | 12 | ToB2 | 317 | Planar |
| Shoth, Droth | Huge | Aberration | Lawful Neutral | 12 | CC | 333 | Planar |
| Skein Witch | Medium | Celestial | Neutral | 12 | ToB1 | 349 | Any |
| Son of Fenris | Huge | Monstrosity | Chaotic Evil | 12 | ToB1 | 355 | Any |
| Stellar Rorqual | Gargantuan | Aberration | Neutral | 12 | ToB2 | 338 | Planar |
| Thrummren | Gargantuan | Celestial | Chaotic Good | 12 | ToB2 | 347 | Mountains |
| Titan, Ancient | Gargantuan | Celestial | Neutral Good | 12 | ToB1 | 380 | Any |
| Titanoboa | Gargantuan | Beast | Unaligned | 12 | ToB1 | 382 | Forests |
| Tosculi, Hive-Queen | Large | Monstrosity | Lawful Evil | 12 | ToB1 | 385 | Desert, Grassland, Hills |
| Undead Phoenix | Huge | Undead | Chaotic Evil | 12 | CC | 361 | Any |
| Venom Maw Hydra | Huge | Monstrosity | Unaligned | 12 | CC | 370 | Swamp |
| Angel, Kalkydra | Huge | Celestial | Lawful Good | 13 | ToB3 | 26 | Planar |
| Angel, Shrouded | Medium | Celestial | Chaotic Good | 13 | ToB3 | 29 | Any |
| Animal Lord, Queen of Scorpions | Medium | Fey | Lawful Evil | 13 | ToB2 | 20 | Desert |
| Archon, Siege | Huge | Celestial | Lawful Good | 13 | ToB3 | 42 | Planar, Urban |
| Bat King | Small | Fey | Neutral | 13 | CC | 22 | Urban |
| Bonespitter | Gargantuan | Monstrosity | Unaligned | 13 | ToB2 | 47 | Grassland |
| Cambium | Large | Fiend | Neutral Evil | 13 | ToB1 | 51 | Ruins, Underground, Urban |
| Carnivorous Ship | Gargantuan | Monstrosity | Neutral | 13 | ToB2 | 56 | Underwater |
| Chaos Raptor | Gargantuan | Monstrosity | Chaotic Neutral | 13 | ToB3 | 81 | Mountains |
| Clockwork Archon | Gargantuan | Construct | Unaligned | 13 | ToB2 | 65 | Urban |
| Demon Lord, Chittr'k'k, of Rats | Medium | Fiend | Chaotic Evil | 13 | CC | 76 | Planar |
| Devil Shark | Gargantuan | Monstrosity | Neutral Evil | 13 | CC | 98 | Underwater |
| Devil, Devilflame Juggler | Large | Fiend | Lawful Evil | 13 | ToB3 | 119 | Planar |
| Devil, Infernal Tutor | Medium | Fiend | Lawful Evil | 13 | ToB3 | 120 | Hills, Mountains, Planar |
| Devil, Orobas | Large | Fiend | Lawful Evil | 13 | ToB1 | 111 | Any |
| Dinosaur, Spinosaurus | Gargantuan | Beast | Unaligned | 13 | ToB1 | 116 | Forests, Swamp |
| Dinosaur, Tricenatorus | Huge | Monstrosity | Unaligned | 13 | ToB2 | 109 | Forest |
| Elemental, Storm Lord | Huge | Elemental | Neutral | 13 | CC | 139 | Coastal, Underwater |
| Equitox | Large | Fiend | Chaotic Evil | 13 | ToB3 | 171 | Coastal, Farmland, Swamp |
| Fey Lady, Countess of Garlands | Medium | Fey | Chaotic Neutral | 13 | ToB3 | 177 | Forest |
| Fiend Lord, Malaabit | Large | Fiend | Neutral Evil | 13 | ToB3 | 185 | Badlands, Desert, Mountains |
| Gigantura | Gargantuan | Monstrosity | Unaligned | 13 | ToB3 | 208 | Underwater |
| Golem, Steam | Large | Construct | Unaligned | 13 | ToB1 | 237 | Any |
| Haugbui | Medium | Undead | Lawful Neutral | 13 | ToB1 | 247 | Any |
| Helashruu | Huge | Aberration | Chaotic Evil | 13 | ToB2 | 197 | Any |
| Incarnate Gloom | Gargantuan | Undead | Neutral Evil | 13 | ToB2 | 213 | Any |
| Life Broker | Medium | Fey | Lawful Neutral | 13 | ToB3 | 261 | Farmland, Urban |
| Mask Wight | Medium | Undead | Neutral Evil | 13 | ToB1 | 285 | Any |
| Nariphon | Huge | Plant | Neutral | 13 | ToB3 | 285 | Badlands, Grassland |
| Nautiloid | Gargantuan | Elemental | Neutral Good | 13 | ToB3 | 286 | Planar, Underwater |
| Necrotech, Bone Colossus | Gargantuan | Undead | Chaotic Evil | 13 | ToB2 | 267 | Any, Underground |
| Noth-norren | Gargantuan | Elemental | Chaotic Evil | 13 | ToB2 | 270 | Grassland, Planar |
| Pustulent Shambler | Gargantuan | Ooze | Unaligned | 13 | ToB2 | 299 | Any |
| Salamander Monarch | Large | Elemental | Neutral Evil | 13 | ToB2 | 311 | Mountains, Planar |
| Stuhac | Medium | Fiend | Neutral Evil | 13 | ToB1 | 370 | Hills, Mountains |
| Tigebra | Large | Monstrosity | Chaotic Evil | 13 | ToB3 | 369 | Forest, Grassland |
| Vampire Warlock | Medium | Undead | Lawful Evil | 13 | ToB1 | 425 | Any |
| Vampire, Psychic | Medium | Undead | Lawful Evil | 13 | ToB2 | 357 | Urban |
| Angel, Uridimmu | Large | Celestial | Lawful Good | 14 | ToB2 | 19 | Planar |
| Azi Dahaka | Huge | Dragon | Chaotic Evil | 14 | CC | 45 | Mountains |
| Butatsch | Gargantuan | Aberration | Chaotic Neutral | 14 | ToB2 | 54 | Mountains, Underwater |
| Cherufe | Huge | Elemental | Chaotic Evil | 14 | ToB2 | 61 | Mountains, Underground |
| Demon, Baliri | Medium | Fiend | Chaotic Evil | 14 | ToB2 | 93 | Planar |
| Dragon, Clockwork, Three-Headed | Huge | Construct | Unaligned | 14 | CC | 113 | Urban |
| Dragon, Mithral, Adult | Huge | Dragon | Neutral | 14 | ToB1 | 133 | Mountains |
| Dragon, Void, Adult | Huge | Dragon | Chaotic Neutral | 14 | ToB1 | 139 | Badlands, Mountains |
| Drake, Liminal | Large | Dragon | Neutral Evil | 14 | ToB2 | 126 | Planar |
| Giant, Cave, Shaman | Huge | Giant | Chaotic Evil | 14 | ToB2 | 171 | Underground |
| Golem, Smaragdine | Large | Construct | Unaligned | 14 | ToB1 | 236 | Any |
| Graknork | Gargantuan | Monstrosity | Unaligned | 14 | ToB2 | 182 | Arctic |
| Grimmlet Swarm | Large | Monstrosity | Unaligned | 14 | ToB2 | 187 | Badlands |
| Howler of the Hill | Large | Aberration | Neutral Evil | 14 | ToB3 | 236 | Farmland, Planar |
| Isonade | Gargantuan | Monstrosity | Chaotic Neutral | 14 | ToB1 | 257 | Underwater |
| Khodumodumo | Gargantuan | Monstrosity | Unaligned | 14 | ToB2 | 229 | Badlands, Hills |
| Queen of Birds | Large | Fey | Chaotic Neutral | 14 | CC | 31 | Mountains |
| Shetani | Medium | Fiend | Neutral Evil | 14 | ToB3 | 343 | Desert, Grassland |
| Sphinx, Gypsosphinx | Large | Monstrosity | Neutral Evil | 14 | ToB1 | 359 | Desert, Grassland, Ruins, Underground |
| Zmey | Huge | Dragon | Chaotic Evil | 14 | ToB1 | 416 | Forests |
| Andrenjinyi | Gargantuan | Celestial | Neutral | 15 | ToB1 | 17 | Any |
| Animated Instrument, Symphony | Gargantuan | Construct | Neutral | 15 | ToB3 | 37 | Urban |
| Arbeyach's Herald, Ia'Affrat | Large | Elemental | Lawful Evil | 15 | ToB1 | 98 | Any |
| Chimera, Royal | Huge | Monstrosity | Neutral Evil | 15 | ToB3 | 83 | Badlands, Forest |
| Cosmic Symphony | Large | Celestial | Unaligned | 15 | ToB3 | 96 | Planar |
| Drake, Star | Large | Dragon | Neutral | 15 | ToB1 | 156 | Hills, Mountains |
| Fey Lady, Mistress of Midnight Teeth | Small | Fey | Neutral Evil | 15 | ToB2 | 146 | Forest, Planar, Urban |
| Fey Lord, Commander of Horn and Gold | Medium | Fey | Lawful Neutral | 15 | ToB2 | 144 | Mountains, Planar |
| Forest Emperor | Huge | Aberration | Neutral Evil | 15 | ToB2 | 155 | Forest, Mountains |
| Giant, Shadow | Huge | Giant | Chaotic Evil | 15 | ToB2 | 173 | Planar |
| Herald of the Great Wyrm | Large | Dragon | Lawful Neutral | 15 | CC | 217 | Any |
| Hvalfiskr | Huge | Giant | Lawful Neutral | 15 | ToB3 | 237 | Arctic, Underwater |
| Lich, Pact | Medium | Undead | Any Evil | 15 | CC | 254 | Any |
| Malmbjorn | Huge | Monstrosity | Unaligned | 15 | ToB3 | 267 | Hills, Mountains |
| Mordant Snare | Gargantuan | Aberration | Chaotic Evil | 15 | ToB1 | 296 | Ruins, Underground |
| Queen of Cats | Large | Fey | Chaotic Good | 15 | CC | 33 | Urban |
| Rakshasa, Greater | Medium | Fiend | Lawful Evil | 15 | CC | 312 | Urban |
| Slow Storm | Huge | Elemental | Chaotic Neutral | 15 | ToB1 | 353 | Any |
| Snallygaster | Huge | Aberration | Unaligned | 15 | ToB3 | 348 | Hills, Mountains |
| Star-Spawn of Cthulhu | Large | Fiend | Chaotic Evil | 15 | ToB1 | 368 | Any |
| Timingila | Gargantuan | Monstrosity | Neutral Evil | 15 | ToB2 | 349 | Underwater |
| Whisperer in Darkness | Medium | Aberration | Neutral Evil | 15 | CC | 378 | Planar |
| Yaojing | Medium | Celestial | Neutral Good | 15 | ToB2 | 377 | Farmland, Forest, Mountains |
| Angel, Ophanim | Large | Celestial | Lawful Good | 16 | CC | 18 | Planar |
| Arcane Leviathan | Gargantuan | Construct | Unaligned | 16 | ToB3 | 40 | Underwater |
| Brother Ox | Huge | Fey | Lawful Neutral | 16 | CC | 25 | Hills, Mountains |
| Cave Sovereign | Huge | Aberration | Chaotic Evil | 16 | ToB3 | 78 | Underground |
| Demon Lord, Bathael, The Exiled Lord | Huge | Fiend | Chaotic Evil | 16 | ToB2 | 87 | Planar |
| Devil, Infernal Knight | Medium | Fiend | Lawful Evil | 16 | CC | 104 | Any |
| Devil, Nephirron | Huge | Fiend | Lawful Evil | 16 | ToB2 | 104 | Planar |
| Dragon, Cave, Adult | Huge | Dragon | Neutral Evil | 16 | ToB1 | 125 | Ruins, Underground |
| Dragon, Flame, Adult | Huge | Dragon | Chaotic Evil | 16 | ToB1 | 129 | Mountains, Ruins, Underground |
| Dragon, Light, Adult | Huge | Dragon | Neutral Good | 16 | CC | 114 | Any |
| Dragon, Prismatic Adult | Huge | Dragon | Neutral | 16 | ToB3 | 142 | Underground |
| Dragon, Sea, Adult | Huge | Dragon | Neutral Evil | 16 | ToB1 | 135 | Underwater |
| Fey Lady, Berchta | Medium | Fey | Lawful Neutral | 16 | CC | 154 | Farmland, Forest, Urban |
| Fey Lady, Snow Queen | Medium | Fey | Neutral Evil | 16 | ToB1 | 198 | Any |
| Fey Lord, River King | Medium | Fey | Chaotic Neutral | 16 | ToB1 | 196 | Underwater |
| Illhveli, Nauthveli | Gargantuan | Monstrosity | Chaotic Evil | 16 | ToB2 | 212 | Underwater |
| Linnorm, Vent | Gargantuan | Dragon | Neutral Evil | 16 | ToB2 | 239 | Underwater |
| Malleable, Massive | Gargantuan | Aberration | Chaotic Evil | 16 | ToB2 | 255 | Any |
| Primordial Surge | Gargantuan | Elemental | Neutral | 16 | ToB3 | 320 | Any |
| Barong | Large | Celestial | Lawful Good | 17 | CC | 49 | Planar |
| Boreas | Medium | Elemental | Chaotic Evil | 17 | ToB1 | 42 | Any |
| Demon Lord, Rangda, of Witches | Large | Fiend | Chaotic Evil | 17 | CC | 79 | Planar |
| Dragon, Boreal, Adult | Huge | Dragon | Chaotic Neutral | 17 | ToB2 | 111 | Arctic |
| Dragon, Wasteland, Adult | Huge | Dragon | Chaotic Evil | 17 | CC | 118 | Badlands, Hills |
| Dragon, Wind, Adult | Huge | Dragon | Chaotic Evil | 17 | ToB1 | 143 | Grassland, Mountains |
| Elemental Locus | Gargantuan | Elemental | Neutral | 17 | ToB1 | 169 | Any |
| Fey Lady, Queen of Witches | Large | Fey | Neutral | 17 | ToB1 | 194 | Any |
| Fey Lord, Moonlit King | Medium | Fey | Neutral Good | 17 | ToB1 | 190 | Any |
| Koschei | Medium | Fiend | Neutral Evil | 17 | ToB1 | 266 | Any |
| Master of Demon Mountain | Medium | Humanoid | Lawful Evil | 17 | CC | 264 | Mountains |
| Sinstar | Tiny | Plant | Lawful Evil | 17 | ToB3 | 345 | Hills, Mountains, Planar |
| Urochar (Strangling Watcher) | Huge | Aberration | Chaotic Evil | 17 | ToB1 | 393 | Ruins, Underground |
| Angel, Angel of Judgment | Huge | Celestial | Neutral | 18 | ToB2 | 16 | Planar |
| Animal Lord, Queen of Mammoths | Huge | Fey | Chaotic Good | 18 | ToB3 | 32 | Arctic, Grassland, Hills |
| Demon, Kogukhpak | Huge | Fiend | Chaotic Evil | 18 | ToB3 | 109 | Arctic, Underground |
| Dragon, Mithral, Ancient | Gargantuan | Dragon | Neutral | 18 | ToB1 | 132 | Mountains |
| Dragon, Sand Adult | Huge | Dragon | Neutral Evil | 18 | ToB3 | 146 | Badlands, Desert |
| Fey Lord, of the Hunt | Medium | Fey | Lawful Neutral | 18 | ToB1 | 188 | Any |
| Golem, War Machine | Gargantuan | Construct | Unaligned | 18 | CC | 205 | Any |
| Lava Keeper | Huge | Elemental | Lawful Neutral | 18 | ToB2 | 235 | Hills, Mountains |
| Bone Lord | Huge | Undead | Neutral Evil | 19 | ToB3 | 65 | Any |
| Dawnfly | Gargantuan | Beast | Unaligned | 19 | ToB3 | 104 | Badlands, Coastal, Swamp |
| Demon Lord, Chemosh, of Conquest | Huge | Fiend | Chaotic Evil | 19 | CC | 75 | Planar |
| Devil, Arch Devil, Poena, Duke of Retribution | Large | Fiend | Lawful Evil | 19 | ToB2 | 99 | Planar |
| Dragon, Felid | Huge | Dragon | Neutral | 19 | ToB2 | 143 | Forest, Grassland, Mountains, Underground |
| Giant, Hraesvelgr, The Corpse Swallower | Huge | Giant | Neutral | 19 | ToB1 | 224 | Any |
| Living Star | Huge | Celestial | Any | 19 | CC | 256 | Any |
| Shoggoth | Huge | Aberration | Chaotic Neutral | 19 | ToB1 | 347 | Any |
| Angel, Zirnitran | Huge | Celestial | Neutral Good | 20 | ToB3 | 31 | Mountains, Planar |
| Baba Yaga | Medium | Fey | Chaotic Neutral | 20 | CC | 46 | Forest |
| Demon Lord, Rhopalocerex, Lord of Deception | Large | Fiend | Chaotic Evil | 20 | ToB2 | 90 | Planar |
| Dragon, Imperial, Adult | Huge | Dragon | Neutral | 20 | ToB2 | 115 | Coastal, Underwater |
| Emperor of the Ghouls | Medium | Undead | Neutral Evil | 20 | ToB1 | 218 | Ruins, Underground, Urban |
| Harbinger of Wrath | Gargantuan | Construct | Chaotic Evil | 20 | ToB2 | 193 | Planar |
| Ankou Soul Herald | Gargantuan | Dragon | Neutral | 21 | CC | 37 | Any |
| Arch-Devil, Arbeyach | Large | Fiend | Lawful Evil | 21 | ToB1 | 95 | Any |
| Demon Lord, Alquam, of Night | Huge | Fiend | Chaotic Evil | 21 | ToB1 | 84 | Any |
| Dragon, Prismatic Ancient | Gargantuan | Dragon | Neutral | 21 | ToB3 | 141 | Underground |
| Dread Examiner | Large | Aberration | Neutral Evil | 21 | ToB3 | 159 | Any |
| Fey Lady, Coral Queen | Medium | Fey | Chaotic Neutral | 21 | ToB3 | 175 | Coastal, Underwater |
| Fey Lady, Queen of Night and Magic | Medium | Fey | Neutral Evil | 21 | ToB1 | 192 | Any |
| Fey Lord, Rainforest King | Medium | Fey | Neutral Good | 21 | ToB3 | 181 | Forest |
| Giant, Mountain | Gargantuan | Giant | Neutral Evil | 21 | CC | 185 | Mountains |
| Gugalanna | Huge | Celestial | Chaotic Good | 21 | CC | 213 | Planar |
| Primordial Matriarch | Gargantuan | Elemental | Neutral | 21 | ToB3 | 318 | Mountains, Planar |
| Shadow of Death | Large | Celestial | Chaotic Evil | 21 | ToB2 | 323 | Any |
| Shoth, Avatar of | Gargantuan | Aberration | Lawful Neutral | 21 | CC | 332 | Planar |
| Simian, Monkey King | Medium | Celestial | Neutral | 21 | CC | 337 | Farmland, Forest, Urban |
| Angel, Archangel Hala’ath | Huge | Celestial | Lawful Good | 22 | ToB3 | 22 | Planar |
| Arch-Devil, Belphegor, Hell's Inventor | Huge | Fiend | Lawful Evil | 22 | CC | 100 | Planar |
| Demon Lord, Camazotz, of Bats and Fire | Large | Fiend | Chaotic Evil | 22 | ToB1 | 85 | Any |
| Demon Lord, Typhon, Father of Monsters | Gargantuan | Fiend | Chaotic Evil | 22 | CC | 81 | Planar |
| Dragon, Light, Ancient | Gargantuan | Dragon | Neutral Good | 22 | CC | 116 | Any |
| Dragon, Sea, Ancient | Gargantuan | Dragon | Neutral Evil | 22 | ToB1 | 135 | Underwater |
| Dragon, Wind, Ancient | Gargantuan | Dragon | Chaotic Evil | 22 | ToB1 | 142 | Grassland, Mountains |
| Fiend Lord, Abhaddanayla | Medium | Fiend | Lawful Evil | 22 | ToB3 | 183 | Mountains, Planar |
| Giant, Jotun | Gargantuan | Giant | Chaotic Neutral | 22 | ToB1 | 226 | Grassland, Hills, Mountains |
| Angel, Archangel Iilari’jil | Large | Celestial | Chaotic Good | 23 | ToB3 | 24 | Any |
| Demon Lord, Hriggala, Jaws of Vardesain | Huge | Fiend | Chaotic Evil | 23 | ToB2 | 88 | Planar |
| Demon Lord, Qorgeth, of the Devouring Worm | Gargantuan | Fiend | Chaotic Evil | 23 | ToB1 | 90 | Any |
| Dragon, Sand Ancient | Gargantuan | Dragon | Neutral Evil | 23 | ToB3 | 145 | Badlands, Desert |
| Dragon, Wasteland, Ancient | Gargantuan | Dragon | Chaotic Evil | 23 | CC | 120 | Badlands, Hills |
| Devil, Arch Devil, The Curator, Hell's Collector | Large | Fiend | Lawful Evil | 24 | ToB2 | 100 | Planar |
| Devil, Arch-Devil Totivillus, Scribe of Hell | Medium | Fiend | Lawful Evil | 24 | ToB1 | 101 | Any |
| Devil, Arch-Devil, Iorvensiav | Gargantuan | Fiend | Lawful Evil | 24 | ToB3 | 117 | Arctic, Planar |
| Dragon, Boreal, Ancient | Gargantuan | Dragon | Chaotic Neutral | 24 | ToB2 | 110 | Arctic |
| Dragon, Flame, Ancient | Gargantuan | Dragon | Chaotic Evil | 24 | ToB1 | 128 | Mountains, Ruins, Underground |
| Dragon, Void, Ancient | Gargantuan | Dragon | Chaotic Neutral | 24 | ToB1 | 138 | Badlands, Mountains |
| Arch-Devil, Parzelon, King of Secrets | Huge | Fiend | Lawful Evil | 25 | CC | 101 | Planar |
| Devil, Arch-Devil Mammon | Huge | Fiend | Lawful Evil | 25 | ToB1 | 99 | Any |
| Dragon, Imperial, Ancient | Gargantuan | Dragon | Neutral | 26 | ToB2 | 115 | Coastal, Underwater |
| Zaratan | Gargantuan | Monstrosity | Unaligned | 26 | ToB1 | 414 | Underwater |
| Demon Lord, Mechuiti, of Apes | Gargantuan | Fiend | Chaotic Evil | 27 | ToB1 | 88 | Any |
| Degmadu | Gargantuan | Monstrosity | Chaotic Neutral | 28 | ToB2 | 84 | Underground |
| Demon Lord, Alsikaya, Screeching Mother of Volcanoes | Huge | Fiend | Any Evil | 28 | ToB2 | 85 | Planar |
| Godslayer | Huge | Construct | Unaligned | 30 | ToB3 | 212 | Any |