How do I set a custom head for a mob?

I am in the process of trying to replace a mob's head armor slot with a custom head.
The /replaceitem command doesn't seem to be working.

/replaceitem 
entity @e[name=Zombie] 
armor.head 
minecraft:player_head{
    Owner:{
        Id:"c6792fd4-414c-477f-8c2c-328df8569253",
        Properties:{
            textures:[{
Value: 
"eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvOTRlNTljNTQ3NmQ5ZTNhMjFjZTE2YmM1MWU2MThhNWVhMjQzN2IzNGU4MTJhZTBjYmExN2FiYWQyOGZlYTEyOSJ9fX0="
}]}}} 1

The head slot is replaced by a regular player head instead of the one I want.

Solution 1:

It's SkullOwner on items for some reason, not Owner. Also of course @e[type=zombie], not @e[name=Zombie], if you want to actually select all zombies instead of all entities named "Zombie" with a name tag.