You see Minishabaal
Notes
This creature shouldn't be underestimated. It can combo a lot of damage in a short time. It only appears in raids. Probably the boss of the Diabolic Imps. Claims to be part of the Ruthless Seven.
Abilities
Self-Healing, Invisibility, Strong Haste, Summons 1-3? Diabolic Imps
Damage Taken From Elements
Physical 
Death 
Holy 
Ice 
Fire
Energy
Earth
Location
North of Darashia
Strategy
Either try to trap it or try to get many SDers to combo it down at low life before it runs away.
Loot
0-9 gp, Fire Axe, Soul Orb, Demonic Essence, Golden Legs (rare), Small Amethyst, 0-3 Surprise Bags, Crown Legs, Demon Shield