Shulker

The Shulker is an upcoming hostile mob in 1.9. It dwells in the End City Dungeons. It hides in its shell to blend in with surrounding Purpur Blocks. The Shulker is a mixed word of Shell lurker

Spawn
Shulkers spawn in an End City Dungeon, which are located on the outer islands of the End.

Appearance
The shell of the mob looks like a purple block. It can also appear on walls.

Attacking
When attacking, Shulkers open up and shoot bullets which only move along the x/y/z axis. However, by using commands, they can be made to be part of a team to attack other teams and can be used as defense mobs.

Shulkers launch projectiles, which run across the X, Y, or Z axis, though they can also change axis. The projectiles can be knocked away by attacking them. If the player gets hit by one, it causes of damage and provides the new levitation status effect.

Trivia

 * Shulkers can be assigned to a team using commands, causing them to attack any mobs and players not on their team.
 * The name Shulker is short for "Shell Lurker".