Endermite

Endermites attack players (and iron golems‌ within 16 blocks of them. If a mob attacks an endermite, any endermites in the area become hostile toward that mob. They can attack endermen when spawned with a spawn egg.‌

Trivia

 * 1) Endermites despawn within 2 minutes, regardless of the player's distance from the endermite, except for when they have been named with a name tag.
 * 2) For being arthropods, they are weak against weapons with the Bane of Arthropods enchantment.