Send massage.
@Background Pony #2684
The Chimera, Bugbear, and manticores are regular (or close to a regular) animals fused through a spell, so they’re technically whatever they contain, i. e. the bugbear is half-wasp, half…well, not a bear, but a giant panda.
The others are bit more wonky. The griffins have bird talons, bird beaks and bird wings, but the rest of the bodies are mammalian in nature, and we don’t even know if they lay eggs. Hippogriffs are described as “part bird, part pony”, so were they also fused via magic and just reproduced from there? Maybe those guys are like the platypus - they got bird-like features but are fully mammalian.
Short answer, mythical creatures don’t gotta obey the rules of our animals.