venom (specify what kind in the tags!)

infinitely regrowing teeth like sharks/crocodilians

movable crest/dewlap like some birds/lizards

tapetum lucidum (the thing that makes eyes reflect light back in the dark)

hands/feet that let you stick to walls like geckos/frogs

mantis shrimp color vision

ability to drop & regrow limbs

something not listed (elaborate in tags)