As the castmember leading our tour was giving us her welcome speech, she suddenly interrupted herself with, "Squirrel!"
We turned around, and sure enough, a squirrel was sitting on the low concrete wall, about a foot behind us, just sitting up and looking at us like he wanted to say, "Please, don't stop for me."
Another time we heard a terrible commotion by the little bridge into Camp Minnie-Mickey at Animal Kingdom. Much squawking and splashing. Looked into the water to see a hawk and a female mallard tussling. The mallard appeared to be trying to drown the hawk (and who can blame her?). Eventually the hawk extricated itself and flapped soggily away, while the lady duck kept quacking, this time like she was calling someone. Finally a male mallard in full colour made his appearance (he'd been hiding a little way downstream) and she settled down.
Then there was the little feral kitten we saw peering at us, from behind a door during the Osborne lights. Soon as he realized we were watching him, he disappeared.
And we once spent a very pleasant meal at the Yak and Yeti watching a bunny forage just outside our window, and commenting on the physical differences between Florida bunnies and Ontario bunnies (ours have longer ears and are bigger).
I love the wildlife around Disney. I get ridiculously excited over spiders and lizards and mallard ducks and bunnies.
Edited to add:
Disney bunny, AKA Marsh Rabbit
Ontario bunny, AKA Eastern Cottontail