Purple Worm

Gigantic, slimy worms with bodies 100’ long and 8–10’ thick. Bore tunnels through the earth and come to the surface to eat other creatures.

AC6 [13], HD15* (67hp),
Att 1 × bite (2d8), 1 × sting (1d8 + poison), THACO 9 [+10],
MV 60’ (20’), SV D8 W9 P10 B10 S12 (8),
ML 10, AL Neutral, XP 2,300, NA 1d2 (1d4), TT D

• Swallow whole: A bite attack roll of 20, or 4 or more than the target number required, indicates that a human-sized (or smaller) victim is swallowed. Inside the worm’s belly: suffer 3d6 damage per round (until the worm dies); may attack with sharp weapons at –4 to hit; body digested in 6 turns after death.
• Poison: Causes death (save vs poison).
• In restricted spaces: May not always be able to bite and sting at once.

Source: Classic Fantasy