Bloodworms

Bloodworms are large carnivorous worms possessed of an aggressive temperament and a venomous bite. They appear in Ultima Underworld I and II.

Description
Aside from their bright green coloration, bloodworms physically resemble their less dangerous cousins, rotworms, and may typically be found in similar swampy environments. Bloodworms, however, are markedly more vicious and their bite carries a deadly poison which may quickly overwhelm an unprepared adventurer.

Trivia

 * In Ultima Underworld II, a large infestation of bloodworms threatens the fishing grounds of a small company of Moglop goblins, and the Avatar may opt to slay them on the tribe's behalf.