Heads are decorative blocks that were shown by Jeb. [1] There are five variants of heads: skeleton, wither skeleton, zombie, human and creeper. They will be very rare drops of these mobs.[2][3]
Use
It is possible to spawn Withers by placing 4 soul sand in a T-formation then placing three wither skeleton heads on the top.
Also, you can wear them on your head, just like pumpkins.