A Skum is a type of aberattion class monster found in Dungeons & Dragons and like all aberattions is alien in design and purpose.

A Skum resembles an ugly, black ordark green fish-humanoid, with muscular limbs, hands and feet which are both webbed and clawed, very veiny and tight-packed flesh, a tail, and fins protruding from the head, tail and underarms.

A Skum lives in watery grottoes and caves in broods of 2 to 5 individuals or packs of 6 to 15. As its name suggests, it is a rather dirty creature, and could be described almost as an underwater equivalent of an ogre or minotaur. They speak Aquan, and are lawful evil in alignment.