Animal names with double letters in them?

Alligator, Baboon, Buffalo, Buzzard, Cheetah, Deer, Ferret, Gazelle, Giraffe, Goose, Gorilla, Hippopotamus, Gull, Kangaroo, Llama, Manatee, Moose, Parrot, Otter, Raccoon, Rabbit, Sheep, Reindeer, Squirrel.