Monster skill

Monster skills are skills used by monsters in Guild Wars that are unique to those monsters.

Monster skills cannot be learned (through Skill Trainers) or captured (through a signet) by players in the game. Also, Mesmer can't "steal" them with spell theft and mimicking skills like Arcane Thievery.

Monster Skills in the Game

 * Agnar's Rage
 * Brutal Mauling
 * Claim Resource
 * Consuming Flames
 * Crippling Attack
 * Crystal Haze
 * Crystal Hibernation
 * Crystal Skin
 * Deafening Roar
 * Giant Stomp
 * Mursaat Tower
 * Nibble
 * Soul Vortex
 * Spectral Agony
 * Wurm Siege

Unique Skills
In addition to skills specific to monsters, some NPCs who accompany players as allies in Guild Wars have unique skills that cannot be learned. These are:
 * Chains of Enslavement
 * "Killroy Stonekin"