So, you would rather fight thousands of undernourished imps?
Ooookaaaayyy.... your funeral.
Invulnerable to fire, cold, electrcity.... check.
Invulnerable to normal weapons (need silver or magical weapons to hit).... check.
Ability to polymorph.... check.
Attacks with insta-kill poison.... check.
Okay, you asked for it, I'll have an evil wizard open a rift and accidentally let in a whole bunch of imps. So, what do you guys what to play in the next adventure?