[UPDATE]
Not even 2 minutes has passed since I posted this. More witches are spawning in random places.

I was exploring the new terrain on my multiplayer world while riding my horse, when suddenly I watched a witch spawn in the middle of the planes biome, nowhere near a witch hut. The world was generated in snapshot 13w36a.

I expected to see normal mobs while exploring.

What happened is a single witch spawned before my eyes.

Steps to Reproduce:
1. Log onto my server.
2. Go to 739 x, 68 y, and 1603 z.