Inner Demon

Inner Demon can be found in Serpentshrine Cavern.

General
Summoned in the Leotheras the Blind encounter as adds. Vulnerable against Holy, Nature and Arcane spells. Simply spam Arcane Blast as a mage.

Leotheras the Blind Info
Leotheras the Blind
 * Summons an Inner Demon from up to five raid members.
 * Inner Demons have approximately 11,000 health.
 * Each Inner Demon can be attacked only by the person it spawned from. If you do not kill your Inner Demon before Leotheras gets back into humanoid form (25-35 sec) you will become Mind Controlled for 10 minutes and can't get out of it unless killed.
 * Inner Demons hit for very little and can easily be healed through, dealing ~1000 damage melee and ~2500 ranged damage.
 * Inner Demons take decreased damage (-20%) from shadow and fire spells.
 * Inner Demons take increased damage (+65%) from arcane, nature, and holy spells.
 * Inner Demons will not be summoned on the person with aggro.

Note that your Inner Demon, if you have one, will be rendered normally, whereas the Inner Demons of other players will appear as black silhouettes.