Depends on a pet. That's SV balancing problem again. Just like trinkets - no middleground, either trash or OP. I understand that pets are much harder to balance then, for example, in UO. If your terrorbird dies, you're in for a wonderful journey into jungle and after that, hours of training. Of course they must be OP to justify ever using them. But it's not good for the game. A pet that you can find in the nearby woods should be viable for PvP at least, and not necessarily at max level. Than top tier pets should be better, but only marginally so - just enough to justify using them in big pvp stuff, like sieges.