In Minecraft you can place down mob heads so you should be able to do the same in poc. Also in Minecraft bedrock if a charged creeper blows up a stray (Cold skeleton) it drops a winter skull so maybe that could be a way to get a wither head to make a wither boss.
Sounds interesting. Thanks for the suggestion! We will consider it.
Yes, a few days ago I was thinking about the same thing about putting heads on the ground like a block
Or an armour stand...