Easter Island Heads are unique mobs that resemble Moai, or stone statues carved by the Polynesian people of Easter Island. They are approximately two blocks tall, the size of a player, and drop Chunk O' Head when killed. Easter Island Heads have a total of 15 health (7.5 hearts).
When spawned, they are "asleep," but when you attack or approach them, their eyes will open and turn red. Swords and axes are useless; pickaxes are the only thing that can hurt them. Wooden pickaxes have no effect. They will attack you when you get in range by jumping toward you and deal significant damage plus knockback. Easter Island Heads move considerably slower while in water, but will still pursue the player. However, if the player moves far enough away from the mob, it will go back to sleep.
Since the Easter Island heads are neutral mobs, they spawn in peaceful mode. Even if on peaceful mode, an Easter Island head will attack if the player is holding a Chunk O' Head block.
Do not confuse them with the generated structure version. If you can go through one and push it, the Easter Island head is a mob.