Boar
What it does: Boars are jerks, and they have bad attitudes. They’ll attack you just for standing in front of them, even if you’re several squares away.
How to make it:
If you can get a Willowisp to stop stealing children away long enough to throw a Forest Shrine at it, they’ll turn into a Boar.
What it makes:
Two Boars combine to make an adorable (and docile) Pig. That’s the best kind of math.