Goblins born with bluish skin who develop magical abilities

Occasionally a goblin is born different, developing a bluish tint to its skin during its childhood; such a creature is called a Boglin. An adult boglin has the abilities of a Magic-user of a level equal to twice the monster's hit dice. In any given goblin lair, there is a 10% chance that 1d4 boglins are present. Larger goblin societies, such as a goblin city or major fortress, will almost always have at least 1d4 boglins. They are almost never encountered alone.