EQ Mob:a keeper of the flame  

In Argin-Hiz: These mobs hit for a max ~15,000 and are immune to mez and stun.

In Argin-Hiz (Rings of Fire): These mobs, as part of the Vasser Fayeil ambush event, are mezzable.

In Argin-Hiz (Burn Out): Part of the Argin-Hiz event "Burn Out" (see this quest entry for details about the group mission and this quest entry for details about the raid version).