Slardar is a Slithereen, one of the Deep Ones, guardian of the great wealth of sunken cities and the ancient riches buried there. In the lightless gulf of the great ocean abysses, the Slithereen Guard carries his lure-light with him through the secret treasure rooms. Subaqueous thieves (sent into the deeps by covetous dryland sorcerers) are drawn in by its friendly glow, never to return. He is utterly loyal, and his taciturn nature hides deep knowledge of the most secret places of the sea. He rises to the shallows in spite of the pain caused him by brightness, to commit reconnaissance, to make sure no one is conspiring against the depths, and sometimes in relentless pursuit of the rare few who manage to steal off with an item from the Sunken Treasury. Because he has spent his whole life at great pressure, under tremendous weight of the sea, Slardar the Slithereen Guard is a creature of great power.
Source: The Game Website.