Phase Lasher

Phase Lasher can be found in Dire Maul.

Tactics
Throughout the fight, they alternate between different "phases". Each "phase" gives them a resistance to a specific magic school (presumed) as well as specific AoE abilities.
 * Phase "by default": Shadow. The lasher is darkly colored and casts Shadow Bolt Volley. The lasher is in this phase when it enters the fight and appears to alternate between it and the other phases (unconfirmed yet though).
 * Nature phase, the lasher is green and casts Thorn Volley, an AoE damaging spell with a short knockdown effect, hits all the party.
 * Frost phase, lasher is white, casts Frost Nova.
 * Arcane phase, lasher is blue, casts Slow on all the party (slows down attack and movement speed).
 * Fire phase, lasher is red, casts Fireball volley.

Notable Drops
Phasing Boots