No. Enc.: 1 (0)
Movement: 210' (70')
Armor Class: 5
Hit Dice: 12
Attacks: 3 (claw, claw, bite)
Damage: 1d6, 1d6, 3d8
Hoard Class: None
Swamp worms (properly known as "hydroids") are not natural mutants or animals, but are rather created through magical forces. They appear to be grotesquely large snakes (between 30-40 feet long) with the head and front claws of an alligator. They have pupil-less red eyes and a bony fin protruding from its head. Since they are brought into existence by wizards specifically to do their bidding, they will never be found "in the wild" or "in a lair." They are blindly obedient to the one who created them.
A swamp worm attacks with its two claws for 1d6 hit points of damage each and with its toothy maw for 3d8 hit points of biting damage. A swamp worm's true magical nature is revealed when it uses its special regenerative capability. When a swamp worm is taken down to one-half of its original hit point total, the worm splits into two halves. These halves then immediately regenerate into a whole swamp worm, each with the remaining hit point total. (For example, a 100-hit point swamp worm is taken down to 50 hit points. It splits, and the two new swamp worms each have 50 hit points.) The new swamp worms will not divide further. Once the swamp worms are defeated, they will curl upon themselves and disappear in a flash of light and acrid smoke.
In the show, Thundarr was able to defeat the swamp worms by tricking them into biting each other. When they made contact with each other, they exploded into non-existence. This method may also work for your PCs, but I have no idea how they'd manage such a trick. If they think of it, let them do it!
Mutations: regenerative capability (one-time duplication)
NOTE: This creature is inspired by the episode “Trial By Terror” from the classic Ruby Spears post-apocalyptic cartoon “Thundarr the Barbarian.” Stay tuned each week for “Thundarr Thursday”!
Musical Monday (Bonus): Guardians Of NYC... - Thanks to Jeremy Hawkins for pointing this out. The dancing and editing on this film is superb.