A Sluggoth demon is a wormlike natural predator demon resembling a giant maggot. The Sluggoth has one large mouth which can expand the width of its body, allowing it to consume large creatures whole. It can burrow through the ground very fast and snatch small pray and burst trough the ground to take bigger.
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.