You see a ravenous lava lurker
Notes
Not only are these creatures immune to Fire, they actually get healed by it. Their relatively low power relative to their experience reward makes them popular targets for players who are focused entirely on gaining experience, regardless of waste.
Abilities
Melee (?)
Fire AttacksDamage Taken From Elements
Physical 
Death 
Holy
Ice
Fire
Energy
Earth
Location
Gnome Deep Hub in the Gnomish area.
Behaviour
They fight in close combat.
A ravenous lava lurker attacks in melee range.
Strategy
Mages can avoid their melee attack by blocking them off using a Crate or Parcel. Using Avalanche Rune as they often come in groups.
History
Until the Update 11.54, these creatures were also called Lava Lurkers, but were renamed to avoid mix-ups.