Canal Worms

It seemed that Canal Worms had died out on the Mars of the late 19th century. However, once filling the canals with fresh water, the adventurer will get an ugly surprise. These worms have survived in hibernation and now are back!

These huge worm-monsters surely are fear-inspiring. Their teeth can cause high damage and it can swallow a person in one move. Thankfully their worm body is also their weakness, as far range attacks will kill it quickly.

Found in canals once they're re-flooded.

Lore
''No human has ever seen one of these creatures, but several circular tapestries found in the Martian cities depict what Lowell believes to have been huge, canal-dwelling worms. Several features are immediately apparent. They had huge maws full of row upon row of shark-like teeth. They must surely have been quite ferocious, attacking anything that moved on or near the canals. And they were large enough to swallow a man whole. Perhaps it is a blessing that the canals are empty and mankind need never fear these awesome beasts.''

- from "Mysteries of the Red Planet", Martian Dreams