Bukkit

What steps will reproduce the problem?
1. Renaming player head Pushable in an anvil.
2. Placing the player head.
3. Pushing the player Head.

What is the expected output? What do you see instead?
The player head does move one block but after that turns into a Skull instead of staying a player head. It does remain pushable though.

What version of the product are you using?
1.1 on spigot 1.8 (also happened on Bukkit 1.7.10)

Do you have an error log of what happened?
No