Vex

A vex is a flying hostile mob that is summoned by another hostile mob, the evoker.

Behavior
Vexes are hostile mobs that attack the player and villagers. Vexes can float through walls, and will attack villagers as commanded by the evoker. When attacking, it turns red. If summon by an evoker, vexes will start to take damage after a certain amount of time, and eventually die. This does not apply if it is summoned by spawn eggs or with the command.

Data values
Vexes have entity data associated with them that contain various properties of the mob. Their entity ID is.