I mean if you remove his dragon form's horns, moustache and legs he's basically literally a giant snake lol.
Speaking of snakes, honestly Kaido should've gotten the Orochi fruit instead.
I feel like it suits his king of the beasts vibe way more, plus the regen actually gives him a reason to not die in fights thus explaining his suicidal nature.
Plus
@moreha9685 had a cool suggestion that his fruit could result in him growing an extra head because of Oden's scar.