Is there a consensus about certain creature types?
Here I list the creature by type. If you feel that a creature doesnt fit as well as the others in this type, call it out, and we an figure out exactly what it is.
Beast
(material origin, Intelligence 5 or lower, strictly nonmagical, able to actually or hypothetically exist in reallife)
Beast origin
(anthropomorphic animal, typically a Humanoid)
• Bulette
• Death Dog
• Grick
• Griffon
• Hippogriff
• Owlbear (nonmagical beast; but 4e Fey, and 1e experimental hybrid)
• Piercer
• Roper (relating to piercer; but in 4e is Aberration, warping rock)
• Worg
Kaiju (Monstrosity)
(beastlike, Intelligence 5 or lower, but unnatural because of impossible size or some magic, such as relating natural stone, earth, metal, crystal, ice, water, air, weather, fire, lightning, sunlight, or plants)
• Ankheg (insect size)
• Basilisk (stone magic)
• Behir (lightning magic)
• Carrion Crawler (insect size)
• Chimera (fire magic, Fiend origin)
• Cockatrice (stone magic)
• Gorgon (metal exoskeleton, stone magic)
• Hydra (extreme regeneration, Dragon origin)
• Mimic (shapechanging)
• Purple Worm (worm size)
• Remorhaz (fire magic, insect size)
• Roc (bird size)
• Rust Monster (metal magic)
• Tarrasque (size, possibly earth magic)
• Winter Wolf (ice magic)
Other creature types:
Aberration
(any native of the farrealm astral dominion, typically exhibiting an aura that inflicts in targets a malignant shapechanging and Evil psychological corruption; note creatures created by aberration magic are typically also Aberrations rather than having an Aberration origin)
Celestial (Supernal)
(any native of a supernal astral dominion; typically Good or at least non-Evil)
• Guardian Naga (Celestial, Humanoid, Beast Origin)
• Sphynx (Celestial, Humanoid, Beast origin)
Dragon
(a specific kind of Beast origin, always a snake blending other kinds of Beasts, such as eagle/bat or lion/wolf/fish, but of high Intelligence and capable of magic effects, ultimately relating to a primordial period during the creation of the material plane; arguably, snakes originate from dragons; note, a nonmagical dragonlike Beast is a "drake", or might be a dinosaur)
Dragon origin
(a creature descending from a Dragon, such as Humanoid dragonborn, or created by Dragon magic, such as Kaiju hydra)
Elemental
(any creature that is MADE OUT OF natural stone, earth, crystal, ice, water, air, weather, fire, lightning, sunlight, stars, planets, or plants)
Elemental origin
(any creature created by the magic of an elemental or immigrating from an elemental plane)
Ethereal
(any native of the ethereal plane spirit world)
Ethereal origin
(any creature created by ethereal magic or immigrating from the ethereal plane)
• Phase Spider (?) (Beast origin, Ethereal origin; might be a Kaiju if Intelligence 5, but has Intelligence 6)
Fey
(any native of the feywild spirit world)
Fey origin
(any creature created by fey magic or immigrating from the feywild)
• Centaur (Humanoid, Beast origin)
• Displacer Beast (Kaiju)
Fiend (Infernal)
(any native of an infernal astral dominions; typically Evil)
Fiend origin
(any creature that is typically Evil that was created by an astral dominion; note, sometimes a typically Good supernal dominion creates such an Evil creature)
• Spirit Naga (Fiend, Humanoid, Beast origin)
Giant
(specific kind of elemental, native to material plane, typically Humanoid, but sometimes shapechanging into a beastlike or other form)
Titan
(a subtype of Giant, typically relating to the astral dominions during the primordial period of the creation of the material plane)
• Kraken (Giant, Titan subtype, Fiend origin, Beast origin)
• Yeti (Humanoid, Beast origin, ice magic; Huge, arguably Giant)
Humanoid
(any creature of Intelligence 6 or higher, that is a unique individual within a group that has a culture, typically with humanlike bipedal body, but necessarily having hand-like means and an instinct to manipulate the environment)
• Doppleganger (Humanoid, Fey origin if relating to changeling)
• Drider (Humanoid, Fey origin, Fiend origin, Beast origin)
• Ettercap (Humanoid, Beast origin)
• Harpy (Humanoid, Fey origin, Fiend origin)
• Hook Horror (Humanoid, Beast origin)
• Lamia (Humanoid, possibly Fey or Fiend origin)
• Manticore (?) (thumbs, language, culture, Beast origin)
• Medusa (Humanoid, Fiend origin)
• Merrow (Humanoid, Beast origin, relating to merfolk)
• Minotaur (Humanoid, Beast origin, possibly Fiend origin)
• Umber Hulk (Humanoid, Beast origin, possibly Elemental origin)
• Yuan-ti (Humanoid, Beast origin, Fiend origin)
Material
(any native of the material plane, having a body made out of physical matter; Material is the default planar origin and is normally unmentioned and is assumed unless mentioning a different planar origin)
Shadow
(any native of the shadowfell spirit world; note, all undead are shadow, but many deathly shadow creatures have never known true life thus are not undead)
Shadow origin
(any creature created by the deathly shadow magic or immigrating from the shadowfell)
• Darkmantle (Shadow, Kaiju, darkness magic)
• Peryton (?) (Shadow origin, deathly magic reproduction; might be a Kaiju if Int 5 but is too intelligent 9)