Other traits are normally the fact that they have fur, and look like mammals, mostly...that's only mostly though! There's some weird members...actually, there's even a whale in this group!

It's the 'Field' grouping-if two pokemon enjoy the other enough, and they're compatible in that sense....you get an egg! You could even get one if that whale and a tiny cat liked each other enough!

[That HOT SKITTY ON WAILORD ACTION OHHHHHHH-] ...whoever is the mother though, that'll be what comes out of that egg...