A malevolent deity outside of the Slam canon. Shadow Lord Coxxus is the patron of adluts and deception. His mythological origins can be traced to the early ideology of Grandgod Church before it accepted Slam as the lord and savior. Since the induction of Slam in Finnish culture, Coxxus's importance has been undermined, and he now caters to goblinkind for self-security. Nevertheless, he still has a few human adherents, though many of them have turned goblin such as Sumac.

Coxxus was reincarnated into the Abbot Cox of the Brotherhood of Adults after subjugating the entire kingdom of Coxenburg by goblinization, using the anguished darkness in the fresh goblin hearts to ascend the Dumply Plane. He used his lifespan as a human to nurture Gabriel Goblin into the fiercest of the goblins to create a goblin lord, a medium who could carry out Coxxus's wishes when Coxxus returned to his world. However, it backfired when Gabriel Goblin just moped instead.

Some worshipers of Coxxus purport that Coxxus's image is that of a huge throbbing cock. Antique Table is very uncomfortable about this.