Swimming through the fetid backwaters of the River Styx as it flows through the bottomless sea rifts of the Abyss comes a tentacled horror known in the nightmares of marines and sailors. Shrroth sometimes pass through the thin barriers between the mortal realm and the underworld. They quickly set up shop along sea lanes where they harry sailors, sink ships for sport, and take prisoners whom they torment and torture mercilessly before devouring them body and soul.

Shrroths are 15-foot-tall demons with the lower torso of an octopus and the upper torso of a copper-skinned humanoid. Its arms end in six-fingered talons, and it wields a wicked trident. A mass of long black hair hangs from its head. Two forward-curving, blackish horns protrude under this tangle of hair. Its lower torso sports a mass of writing tentacles reaching lengths of 10 feet. Six larger tentacles stretching 20 feet surround the smaller tentacles. The creature's mouth is a jagged wreck of sharks teeth.