Legendary Creatures Rising

Pigs don't fly and chickens don't breathe fire. Or do they? There's a place where they do, but humans want to study them for their secrets. Humans are generally not very nice when it comes to studying animals, cutting them open and what not while imprisoning the rest. So inevitably someone will rise up and free everyone in these sort of situations. It just so happens that our heroes this time is a pig and chicken.