Zombies and skeletons can spawn with pumpkins on their heads on normal difficulty

Zombies and skeletons can spawn with pumpkins on their heads on normal difficulty. (May be issue caused by TMI)

What I expected to happen was...:
I thought zombies and skeletons would spawn with armor on.

What actually happened was...:
They spawned with pumpkins on their heads!?

Steps to Reproduce:
1. Open a minecraft world.
2. Play in peaceful mode at night.
3. Shift to normal mode.