How about any animal in a costume? Or costumes of animals to make it a bit of a broader topic? So, "animal costumes". Just an idea.
I hate animals in costumes. Not the animals themselves, but pictures of them, because I can't help but think they must be very uncomfortable in these things, and they can't even understand what they are for. Makes me want to call the animal protection groups.
Costumes of animals, though, sounds intriguing.