Put the summary of the bug you're having here

What I expected to happen was...:
I get a Zombie Pigmanplayerhead in my Inventory

What actually happened was...:
I got a normal Player Head with the Tag *(+NBT)*

Steps to Reproduce:
1. Press the Mouse wheel
2. Press CTRL at the same time
3. While doing that, look at a Player Head with a SkullOwner

Edit: Here´s a Link to a Video that explains it: 

https://youtu.be/TUmOJiPv1W8