Small elemental humanoid (demon)
Elemental Companion

HP 1; a missed attack never damages the companionDefenses your defenses, not including any temporary bonuses or penalties
Speed land 4

Passive Benefit: Vicious

You gain a +2 power bonus to opportunity attack rolls.

Passive Benefit: Rattle the Cage

Whenever you end the encounter with the hordeling in passive mode, you take damage equal to your level.

Active Benefit: Standard Action (fear) Encounter

Effect: The hordeling can push each creature adjacent to it 1 square.

Active Benefits: Immediate Interrupt Encounter

Trigger: You or the hordeling takes acid, cold, fire, lightning, or thunder damage.

Effect: You and the hordeling each gain resist 5 to the triggering damage type, or types, until the end of your next turn (10 at 11th level and 15 at 21st level).

Published in Heroes of the Elemental Chaos, page(s) 149.