Aarakocra
MM2014 details the region of the Plane of Air that they live in while describing the war between the Wind Dukes of Aaqa and the Queen of Chaos and their role in opposing Elemental Evil. MM2025 greatly reduces this to what kinds of birds they might look like and mentions the Queen of Chaos and Wind Dukes in passing.
Aboleth
MM2014 states that the aboleths are Primeval creatures that demand worship, lair in watery environments, gain new memories from creatures they eat, and reform in the Plane of Water when destroyed. MM2025 has most of the same details but states that their watery lairs are made in aquatic ruins or places of high magic. The statblock now has them reforming in the Far Realm by default instead of the Plane of Water.
Air Elemental
In 2014 the Air Elemental is part of the Elementals entry, which states that elementals don't take form unless forced to by magic, dislike being summoned, and can be shaped by magic into specific varieties. They are said to like racing along the ground in addition to flying. In MM2025 there is no overarching Elemental entry, and Air Elementals are said to either be summoned or appear around nexuses of planar energy.
Animated Objects
The primary difference between 2014 and 2025 is that the former says some animated objects might be able to speak while the latter makes no mention of this.
Ankheg
Both the 2014 and 2025 Monster Manuals describe how they burrow and hunt for farm animals and game and suggest things that could be found in their tunnels. The main new innovation is that while 2014 implied ankhegs were solitary the more recent book states that multiple ankhegs can congregate where there is plentiful food.
Arcanaloth
MM 2014 has them as part of the Yugoloth entry that details the group's origin, mercenary nature, that they return to Gehenna when destroyed, the four Books of Keeping that hold their true names, and the ultroloth called the General of Gehenna. The 2025 Monster Manual lacks an overview for Yugoloths. The arcanaloth-specific section in 2025 lacks the details that they keep records for yugolothkind and serve as diplomats and negotiators.
Assassin
While there was no lore given for them in 2014, MM2025 states that most assassins kill for a reason and provides a 1d6 table of things an assassin may be infamous for.
Awakened Plants
Another creature with no lore in MM2014, the MM2025 states that spells such as Awaken and magical influence create Awakened Plants, though some plants might naturally be awakened. Awakened Shrubs might be animate topiaries, while Awakened Trees can be created by the Feywild or the Shadowfell's influence.
Axe Beak
The 2014 Monster Manual simply states that the axe beak has a nasty disposition. MM2025 has more details, saying that axe beaks have different plumage in different environments., can hunt alone or live in packs, and that giant axe beaks dwell in Primeval realms and compete with dinosaurs.
Azer
The 2014 entry for Azers is full of information, saying that the creatures are master crafters, reproduce by sculpting and being imbued by the crafter azer’s inner flame, have a contentious history with the efreets and could help those acting against them, and specifies that azers value metal and gems. The 2025 Monster Manual cuts everything other than the azers being made of living bronze and being master crafters.
Balor
Identical to 2014 Lore, though without a demon section there's two pages of general demon lore missing
Bandits
Adds table of 1d6 Bandit Motivations.
Banshee
MM 2014 states they are formed from the spirits of female elves who used their beauty to control others instead of using it to “bring joy to the world”, whatever that means. Banshees covet beautiful objects but hate seeing their own reflections.
MM 2025 says any soul tormented by bitterness or sorrow can become a banshee, but that some Elven communities say they are associated with those who hoarded or destroyed beauty. Includes a list of 1d6 Banshee Sorrows.
Barbed Devil
Without a dedicated devil section some general lore on devils has been omitted from MM2025. Other than this, Barbed Devils actually get much more lore than MM2014, which pretty much just said they work as guards to more powerful devils. MM2025 adds that they also scour the planes for treasure, serve as accountants in addition to guards, maintain networks of imp spies, build specialized hoards that focus on one type of item, and refuse to steal. The Barbed Devil statblock includes the Diabolical Restoration trait.
Barlgura
MM2014 states simply that barlgura gather in packs and keep trophies from their kills. MM2025 keeps all this and adds that when prey becomes scarce the barlguras turn on each other, that they can bear features of predators common to the area, and embed trophies in their own flesh.
Basilisk
The MM2014 Basilisk entry state that basilisks born in captivity can be trained to avoid meeting the gaze of its master and those it designates, and therefore Basilisk eggs are valuable. It further states that fluids within a basilisk's gullet can be processed to cure petrification. Unfortunately, MM2025 omits all this in exchange for a 1d8 table of Petrified Basilisk Victims with entries like an adventurer wearing an ornate key or random animals.
Bearded Devil
MM2014 states simply that the Bearded Devil is a shock trooper with a hair trigger temper. MM2025 expands on this slightly to state that they encourage the mortal tyrants they work for to greater evil.
Behir
MM2014 describes behirs as favoring out of the way lairs and that they were created by storm giants to fight dragons. MM2025 alters this slightly to say that storm giants created behirs by altering blue dragons and that they attempt to eat dragon eggs.
Beholder
MM2025 essentially restates the lore from MM2014, albeit with a little less specifics on beholder lairs.
Berserkers
The primary difference between MM2014 and 2025 here is that berserkers are no longer said to hail from “uncivilized lands”.
Black Dragons
MM2014 states that black dragons are the most evil and sadistic chromatics that collect the treasures of fallen civilizations. Their presence creates shambling mounds, and they use lizardfolk and kobold underlings while trying to undermine other dragons. They toy with their prey, creating false means of escape. MM2025 reduces a good bit of this general lore, paring it down to black dragons wishing to destroy things and rule over the ruins while hoarding tarnished symbols of hope. In exchange, each age category now gets some lore. Young Black Dragons now ally with powerful undead or aberrations, Adult Black Dragons amass cultists and undead, and ancients use undead and fiends to try and kill every other living thing other than themselves.
Black Pudding
Neither the 2014 and 2025 Monster Manuals have a lot of lore on these oozes, but the newer book has a table of possible supernatural origins for black puddings that includes ancient black dragon saliva, the embodiment of a foul deity's emotions, and cosmic entropy.
Blights
Most of the 2014 Monster Manual group entries were broken up in 2025, but not the blights for whatever reason. The general lore section is shorter, omitting the backstory for the Gulthias Tree from The Sunless Citadel and moving an abridged version to the Gulthias Blight entry. Twig Blights lose the detail that they can root in soil, Needle Blights lose the detail that they alert others with pollen, and Vine Blights lose the detail that they are connected to a Gulthias Tree. Tree Blights are added and are said to attack awakened trees and treants.
Blink Dog
The 2025 version loses the detail that they attack displacer beasts on sight in favor of saying they accompany Feywild folk on hunts.
Blue Dragon
Both MM2014 and MM2025 describe Blue Dragons as hunting over deserts and other bare terrain and collecting talented humanoids to cow into service. Whereas MM2014 emphasizes them as a threat to desert-dwelling civilizations, MM2025 talks about them seeking lairs near sites of symbolic power, and Ancient Blues even seek to seize control of world-spanning empires or facets of reality like storms.
Bone Devil
MM2014 simply describes bone devils as the taskmasters of the Hells. MM2025 replaces this with bone devils being the slayers of creatures who don't follow through on infernal deals, executors of diabolical orders throughout the multiverse, and ally to mortal tyrants.
Bone Naga
The MM2014 describes nagas in general as immortal guardians of knowledge and treasure created by a vanished humanoid species; they are also said to be enemies of the yuan-ti, and bone nagas in particular are created by yuan-ti to desecrate defeated nagas. MM2025 expands this by saying that bone nagas have gaps in their memories, most are created from spirit nagas, and that those made from guardian nagas can still be good but have addled minds.
Brass Dragon
MM2014 describes brass dragons as accumulating information via conversation (and being pushy about it) and living in hot climates. MM2025 retains this but adds that they are travelers who build world-spanning information networks between allies over their lives.
Bronze Dragon
The Bronze Dragon of the 2014 Monster Manual inhabits coasts, sneaks onto ships under magical disguise, and is interested in warfare and helping armies fighting for just causes. The 2025 Monster Manual drops the interest in warfare and replaces it with an interest in helping good individuals and civilizations develop and solve problems. Ancient Bronze Dragons seek to protect whole regions or even planets as well as solving multiversal threats.
Bugbear
In 2014 Bugbears serve as scouts, worship the god Hruggek of Acheron, and function as mercenaries. In MM 2025 the Bugbear is another creature with a very short entry, so all of this is replaced with Bugbears being fey embodiments of the fear of nature and very stealthy.
Bulette
The 2014 bulette dislikes elf and dwarf flesh, favors eating halflings, has a hunting territory thirty miles wide, are solitary, have a mating ritual that ends with the male dead and eaten, are possibly the fusion of snapping turtle and armadillo infused with demon ichor, and have young that are almost never seen. None of this is present in the much shorter MM 2025 entry, and young bulette pups are present as pack hunters (the presence of the pup's statblock ate up the space for the information from 2014).
Bullywug
Another creature who gets a lore-ectomy in 2025 because of an extra statblock. In MM 2014 the bullywugs are “thoroughly evil”, have a civilization that rewards cleverly murdering rivals with advancement, and serve petty lords. 2025 eschews all of this and calls them fey embodiments of swamplands who train giant frogs.
Cambion
The first and most surprising difference between cambion lore in the Monster Manuals is that 2025 explicitly states they are made from transformed mortals, whereas the 2014 Monster Manual says they are the offspring of a fiend and humanoid. In both 2014 and 2025 they are inherently evil, the former “born to be bad” and the latter supernaturally compelled. The new Monster Manual 2025 is less specific about how they fit into fiendish plans. MM2014 has a section describing how the demon lord Graz'zt has sired many cambions through copulating with women who made pacts with him, which MM2025 omits in place of referencing Iuz of Greyhawk as a notorious cambion. It is accompanied by a 1d6 table of Cambion Origins that includes being resurrected by an evil spellcaster or making a bargain with a fiend.
Carrion Crawler
The MM2025 entry is mostly the same info as 2014, albeit without some of the specifics from 2014 about how long a carrion crawler will follow a light source and where they drag their meals to eat them.
Centaur
The centaur got a new statblock in 2025, so of course it has a lot less lore text (I like the new statblocks, BTW, but it's weird to me how many monsters now have less descriptive text than Awakened Plants do now). I imagine the reduced lore is partially because the description in the 2014 Monster Manual paints them all as being reclusive and nomadic hunter-gatherers who leave behind centaurs that can't keep up. What lore we do have in the new book is about them being Fey warriors who defend nature sites of primal power.
Chain Devil
The MM2014 describes Chain Devils solely as jailers and torturers. MM2025 only adds that chain devils encourage mortals to learn forbidden magic along with a 1d4 table of chain devil disguises.
Chasme
MM2014 states that chasmes are interrogators, tasmasters, and torturers that capture demons who have deserted their masters. Unlike the other fiends so far they don't really have anything new lorewise in MM2025.
Chimera
MM2014 tells us that Demogorgon mashed some creatures together to create the first chimeras, whereas MM2025 gives no origin for the monster. Like the bulette entry earlier, specifics on the creature like the size of its territory and how it interacts with certain creatures noted in 2014 are absent in 2025, though both agree they can be appeased with treasure and food.
Chuul
MM2014 states that chuuls were created to serve aboleths and collect magic items, doing the latter on instinct and waiting on a new aboleth to continue doing the former. MM2025 sums all this up much more succinctly than 2014 did while also adding that other intelligent aberrations can command them now, as well.
Clay Golem
In 2014 golems were grouped together and had a half-page of general information that boiled down to them being powered by earth elementals and commanded by special amulets. Concerning clay golems in particular, we're told that they are created by priests but go berserk if the bound elemental tries to break free. In 2025 the general entry has been omitted, as have references to elementals and priests. Instead we are told that they are created to guard places and communities using special clay sourced from those places. A table of 1d4 Clay Golem Orders is included.
Cloaker
MM2014 details cloaker hunting habits and that they communicate through subsonic moans, both details omitted in MM2025. Both entries agree on them being largely solitary and only rarely and temporarily congregating. New to MM2025 is that cloakers terrorize their prey and “whisper eerie riddles to those they're about to consume”.
Cloud Giant
The 2014 entry for Cloud Giants details how they interact with giants below them in the Ordning, that they keep aeries of flying monsters, pay homage to the deity Memnor, earn their place in the Ordning via wealth, and wager money on the outcomes of wars. All of this is missing from the 2025 entry (as is the general information on giants), which only states that they view themselves highly and either consider the affairs of the world below something to interfere in or something to watch from afar.
Cockatrice
Both the 2014 and 2025 Monster Manuals describe cockatrices as ornery. 2014 states that they eat nuts, berries, and small animals, but these dietary details are omitted in 2025 to instead tell us they like to lair in abandoned structures.