I'm thinking new forms for those that don't already have them. To make it balanced, I wouldn't use a school that's already been used for beastforms three times. Here are my ideas for three new beastforms following these conditions.
Colossus: A different kind of heal then the Life Draconian. It focuses more on direct healing, with more spells of that variety. These heals would be a bit weaker, but would often often have a secondary effect (such as adding a small absorb) or a condition (Heals more if your friend is under half health.) It would have more health, too.
Draconian: Sort of a cross between the Fire Elf and the Fire Minotaur. Its health and power are sort of in-between those two.
Ninja Pig: A crafty fellow more designed to annoy and weaken the enemy. Not as good in a battle as other beastforms, but its weaknesses, traps, possibly even stuns and dispens make it an excellent support for the team.