Recently I have been seeing an alarming number of novice wizards showing up in the arena using school pets such as Helephant and Hydra to battle. They just wait or shield until their pet card comes up, then attack. This is very discouraging to other novice players.
Boss drop and promo pets are fine, they don't have an all-powerful spell like school pets do.
One thing I can also suggest is that they make these pets Level 45+ only or No Trade.