Cave Worm

Cave worms are gigantic scavengers that bore through the depths of the world, eating whatever material they find. Named for their distinctive habitats, these worms are ravenous and display overwhelming destructive capabilities.

Benthic Worm (Creature 15), Cave Worm (Creature 13), Magma Worm (Creature 18)

The adventure need not end simply because the party was ingloriously swallowed whole by a giant worm. Perhaps the PCs find an undigested item that helps them survive the inhospitable environ, or maybe the worm regurgitates them in a cavern far off from where they started.