A strange and horrifying creature of the earth's deepest places, larger than an ogre but capable of squeezing through tiny openings. When hungry, the underworm will burrow behind the walls of a cavern and lurk dormant and motionless -- often for months -- until it can feel the telltale vibrations of nearby prey.
Underworms only appear encased in statues. They are powerful monsters, but they move slowly, so they are easy to kite. Any means of attacking at range will deal with them painlessly.