Once Seal was unmasked, I realized I missed the most obvious clue to his identity. I was wondering why he chose the leopard as his costume and then I remembered there's an animal called a leopard seal so it all made sense!
The way he dressed and acted made me think initially it could be RuPaul but that definitely wasn't RuPaul's voice.
I agree with waywyrd. I'm 100% sure that Rottweiler is Chris Daughtry.
Recently, I've been wondering if Flamingo is Karyn White. Her voice sounded like that in the 80's but I don't know if she still sounds the same now.
I don't think I know who Fox is. Sometimes they sound like Wayne Brady but other times, not so much. It's probably someone I could never guess.