You see a pillar of draining.
Notes
When its health hits zero it becomes a Destroyed Pillar. Found during the Carlin Cult of the Cults of Tibia Quest.
Abilities
Mana Drain (0-400+)Damage Taken From Elements
Physical 
Death 
Holy 
Ice
Fire
Energy
Earth
Drown
Location
Behaviour
They cannot move.
Strategy
Unknown