The shark. Just because I think it would run rings around the bear. Unless the bear has the sense to get out of the water. As for John Cena - He's a big muscly actor. I know Google says wrestler but that's just an actor. He couldn't win a real fight against a mere man let alone a bear or shark. Chuck Norris has to be infirm by now isn't he? Did you make up "one punch man"?