Ten men, a five-legged horse, and twelve passengers

I am ten men. I am a horse, and in that character I have five legs, and can carry twelve persons. I am a man, and have two legs, and can walk eight. I am a woman, and have four legs, and can walk sixteen. I am a bird, and have two legs, and can fly twelve. I am a fish, and have fins, and can swim ten. I am a beast, and have four legs, and can creep twelve. I am a fly, and have two legs, and can walk four. I am a moth, and have wings, and can fly eight. I am a serpent, and have nine legs, and can go twelve.