Getting bulls should be easy enough, but a bear would be a bit trickier. Then again, gotta figure that there's an animal trainer somewhere that would have a bear that they would trust to saunter along with a crowd, provided they take a few precautions with it like a muzzle and make sure he's got a big full belly.
Ah, but the fun is in the danger. I was thinking of rounding up a few unwanted grizzly bears from the Yukon.