Skum

From publisher blurb: This release of The Manual of Mutants & Monsters provides game stats on the Skum, a subterranean, aquatic race that has been enslaved by the malevolent aboleth. Includes game information on the skum race, as well as the advanced angler variation. Rounding out this product are two caper ideas for using skum in your game, suggestions on how to combine skum with Cthulhu if the latter is a factor in your game, and 1 new advantage.