Head

Mob heads are decorative blocks. There are five variants of mob heads: Skeleton, Wither Skeleton, zombie, human and Creeper. While the Wither skeleton skull can be obtained as a rare drop from Wither skeletons, the other heads are only available in Creative mode.

Uses
The main use of heads is as decoration. They can be oriented in 16 different directions on top of a block, and 4 directions on the sides of blocks, similar to signs. They cannot be placed on top of each other.

Wither skeleton skulls are essential for spawning a Wither. To do so, place 4 soul sand in a T-shape, then place three wither skeleton skulls on top. The orientation of the skulls does not matter.

The player can also wear heads as disguise, similarly to pumpkins. This will only replace the first layer of the player's skin. If the player has a second layer over their head, it will still render over the head. They can also be used as a decorative disguise, using dyed leather armor. Heads are not able to be pushed by pistons, as they have tile entities.

Trivia
Note* Using the and other inventory hacking commands to give the player a mob-head block will give the player a flat-looking soul sand.
 * When breaking any head, the particle effect of breaking it is the same as soul sand.
 * All heads are the same scale. Because of this, even though Wither Skeletons have larger heads than the other represented mobs, their dropped head is the same size.
 * Heads are one of the few blocks that do not use terrain.png and take their textures from other objects.
 * Heads will break upon contact with water and lava.
 * If you were to change the texture of a mob's head, the head will change too but will not render hats.
 * Heads can be worn by zombies, skeletons, and zombie pigmen.
 * It has been reported that sometimes a head has been dropped when a monster was killed by another monster, a skeleton killing a zombie gave a zombie head and skeleton killing another skeleton dropped a skeleton head, it is unknown if this is intended and if it is only if a skeleton kills it. It also seems extremely rare