Pet spells* need to have a pip cost because many are too powerful to simply be 0 pips. I started a new Ice wizard with an Epic Polar Bear Cub. That means at level 2 I was running around with 2 Woolly Mammoth spells in my deck (a 7 pip cast). The base damage of that spell is 600 - 700. Simply put, I would have sailed all the way from Unicorn Way through Celestia quite easily.
John RavenCatcher - lvl95 John StormWalker - lvl95 John DragonPyre - lvl48 John FrostShard - lvl34