Some Hatchlings are pretty aggressive, especially after a change in environment. In the wild they need to be aggressive if they want to survive. Hissing and striking are their only tools to scare away a hungry predator if camouflage fails. Usually they will tame out as they put on size. I haven't personally met a Ball Python that has a personality like BHB's Satan (she's a burm.) She just seems mean spirited. =)