Jubilex in Pathfinder, Juiblex in the world’s oldest role-playing game, Szhublox in Gary Gygax’s novels—by any name he (it?) is the Lord of Slimes and Oozes, and omoxes are his favorite minions.
But he isn’t exactly a demanding lord, so omoxes pretty much do as they please. And you can do as you please with them too, because they’re incredibly easy to insert into a campaign. Demon haunting the sewers? Omox. Scary thing in the wizard’s cauldron? Omox. A mudslide pollutes a profane spring? Omox.
A murder has been committed. The suspect fled into the sewers, and divination reveals he died there. But the magistrate demands his corpse bear testimony at the inquest (courtesy of speak with dead). Someone has to go into the sewers and find the body…which is currently still nestled inside the gooey form of the omox who smothered him.
The makers of a vile transmutation sludge have summoned an omox to guard their chemical plant. As a fail-safe, the evildoers warded the floor against the demon and teleport effects, so it attacks intruders by leaping from vat to vat or using its fogs/clouds and dropping from the ceiling onto adventurers when they are atop machinery or conveyer belts. If the battle turns against it, the omox tries to get to the drainage spillway where the contiguous flow of sludge will allow it to dimension door into the river and escape.
Part of a human mercenary troop quartered in the elven city of Wythrohen during the Rescue of Ilvendish, Argus Mazzerick buried his dagger in the city’s famous White Tree—up to the hilt, for no reason than because the Tree was there, and it was beautiful. The living artifact took ill, and to this day no leaves grow on the Tree’s western face. Mazzerick died in the siege, and in the Abyss his soul took the form of an omox. Though he does not remember anything else about his mortal life, the desire to finish what he started obsesses the demon.
—Pathfinder Bestiary 2 79
The omox is one of the only demons I’ve actually fought as a player. At least I think it was an omox. It was some kind of sludge demon, and it sucked.
I should have mentioned yesterday that if you were lamenting the lack of ogre spiders, rest easy—they are lurking in the giant crab spider entry.