Concocted in some eldritch laboratory of the ancient Serpentmen as a living engine of war, the Chuul is a horrible mix of crustacean, insect, and serpent. This abomination lurks submerged or partially submerged in murky water, awaiting intelligent prey to devour. Although amphibious, Chuuls are not good swimmers and actually prefer to be on land or in very shallow water when they attack. A Chuul is about 8 feet long and weighs 650 pounds. A Chuul prefers to wait by the shore, submerged in murky water, until it hears nearby prey (in or out of the water) that it can attack with surprise.
The Chuul grabs with its claws and constricts its foe, then passes the opponent to its paralytic tentacles. It tries to always have one claw free, so if it faces a large number of opponents, it drops a paralyzed or dead victim and continues attempting to grab, constrict, and paralyze the rest. On a successful hit by a Chuul's claw, it is also able to constrict a victim for an additional 3d6+5 points of damage. The constriction continues on subsequent rounds. The hold may be broken on a roll of 1 on 1d6 (add the victim’s Strength bonus to the range, so a Strength of 16 would result in a range of 1-3 on 1d6); breaking the hold takes a full round.
A victim grabbed by the Chuul's claw are also grasped by its tentacles, which exude a paralytic secretion. Anyone held in the tentacles must make each round a save vs. paralysis on the Chuul’s turn or be paralyzed for 6 rounds. While held in the tentacles, paralyzed or not, a victim automatically takes 1d8+2 points of additional damage each round from the creature’s mandibles. Chuuls may live indefinitely on land and under water and are immune to poison and disease.