A Sluggoth demon was a worm-like natural predator demon resembling a giant maggot. According to Spike, the species had supposedly become extinct around the time of the Crusades. Anya once transformed an abusive boyfriend into a sluggoth demon when his girlfriend wished he was a worm, but undid the spell.
Sluggoth Demons had large, single mouths which expanded the width of its body, allowing it to consume large creatures whole. It could burrow through the ground very fast and snatch small pray and burst through the ground. According to Anya, Sluggoth Demons were in the same phylum as normal worms.