Well given the context you probably wouldn't be able to play a predator... predators would probably be monsters only... then again some versions allows you to play monstruous adventurers... Anyway! Depending on you class you could totally end up turning permanently into lava, you'd need to level up, it would possibly be a last level reward but you could do it! And before that you could get some temporary tranformations. I can think of at least one way of getting that result in Pathfinder using the regular rules and depending on how much we homebrew it there could be others.