Minecraft wiki entry for Evoker, associated text: Entity data
Tags common to all entities[show]
 Owner: The UUID of the entity that that fired the fangs, stored as four ints. If the entity is an Illager, the fangs do not damage other Illagers.
 Warmup: Time in ticks until the fangs appear. The fangs appear and begin to close as soon as this value becomes zero or less; negative values simply result in no delay. The value continues ticking down while the closing animation is playing, reaching -20 on naturally spawned fangs.