Evoker

Evoker is a Hostile Mob that will be added in Update 1.1.

Spawning
Evokers spawn naturally in certain rooms of a Woodland Mansion. They will not respawn after their initial spawn, thus there are a limited number of them per world.

Behavior
Evokers attack The Player, Villagers and Iron Golems within a 16-Block range.

Offense
The Evoker has two attacks - a Fang Attack and Vex Summoning.

Fang Attack
The Evoker signals this attack by producing mauve smoke and a deep horn-like sound. A number of fangs rise out of the ground, then snap shut and vanish. These deal Hearts of damage to all Mobs.

This attack has two forms: offensive and defensive. The offensive form is used if the target is more than three blocks away, the defensive form if they are closer.

Vex Summoning
The Evoker signals this attack by producing off-white smoke and a higher-pitched horn-like sound. Between 2 and 4 Vexes appear nearby.

Combat
Wearing Diamond Armor makes the Evoker's attacks almost negligible, and makes it possible to use a strong melee weapon, like a Diamond Sword. However, if health is low and Armor is not available, a Bow is best.

Trivia

 * Evokers are one of two Illagers - the other being the Vindicator.