There is no animal that has a long o at the beginning.
Orang-utan is a type of rainforest animal that starts with an 'o' at the start of it's name.
maybe okapi will fit.
opossum
Opossum. They're nocturnal animals and their name begins with o.
orangatang
Well, honey, if we're talking about animals, the second letter of a name that starts with a D could be an "O" in a word like "dog" or "donkey." But hey, I'm not here to play guessing games, so if you've got a specific animal in mind, spill the beans and I'll give you a straight answer.
Orangutang Opossum
· Opossum · Otter
Old English SheepdogOx
O Henry
open
Orbit