Mob's Skills - One Command Block Creation

Hello, this is one of my first One Command Creation, It adds Mob's Skills in Vanilla Minecraft
I hope you enjoy it :)
(I'm sorry if i make mistakes, I'm not English)

How to get a Command Block : type in the chat : /give @p minecraft:command_block
How to make the machine work : copy and paste the command below inside the Command Block and power it

The Command : http://pastebin.com/xRytnhXx

Instructions
Throw a Diamond to a Mob, You will get a Boss, If you kill the Boss it will drop his head, wear the head in order to get his skills.
Don't Place the head on the ground, it won't work anymore.
Bosses are pretty tough.

For now there are only six Mobs available
Blaze
Enderman
Creeper
Zombie
Skeleton
Spider

I might add more Mobs in the future

use this command on Minecraft 1.8 or above

Please comment if you like it and for any suggestion or if you find any bugs :)