The behir is a snake-like reptilian monster whose dozen legs allow it to move with considerable speed and climb at fully half its normal movement rate. It can fold its limbs close to its long, narrow body and slither in snake-fashion if it desires. The head looks more crocodilian than snake-like, but has no difficulty in opening its mouth wide enough to swallow prey whole, the way a snake does.
Behir have band-like scales of great hardness. Their color ranges from ultramarine to deep blue with bands of gray-brown. The belly is pale blue. The two large horns curving back over the head look dangerous enough but are actually used for preening the creature's scales and not for fighting.
A behir will attack its prey by first biting and then looping its body around the victim and squeezing. If the latter attack succeeds, the victim is subject to six talon attacks next round.
A behir can discharge a 20-foot long stroke of electrical energy once every 10 rounds. This lightning bolt will cause 24 points of damage unless a saving throw vs. breath weapon is made. In the latter case, the target takes only half damage.
On a natural attack roll of 20 the behir swallows man-sized prey whole. Any creature swallowed will lose 1/6 of its starting Hit Points each round until it dies at the end of the sixth round. The behir will digest its meal in 12 turns, and at that time the victim is totally gone and cannot be raised from the dead. Note, however, that a creature swallowed can try to cut its way out of the behir's stomach. The inner armor class of the behir is 7, but each round the creature is in the behir it subtracts 1 from the damage each of its attacks does. This subtraction is cumulative, so on the second melee round there is a -2, on the third a -3, and so on.
Behir are solitary creatures, meeting others of their kind only to mate and hatch a clutch of 1-4 eggs. The female guards these eggs for eight months while the male hunts for the pair. When the young hatch, they are immediately turned out of the nest to fend for themselves, and the adults separate.
Newly hatched behir are about 2 feet long. Behir grow at a rate of 8 feet per year until fully mature. Interestingly enough, newly hatched behir do not have all of their legs, having instead only six or eight. Additional pairs of legs grow slowly over time until the creature has its full complement when it reaches adulthood.
Behir range over a territory of about 400 square miles, often living high up a cliff face in a cave.
Behir are never friendly with dragonkind, and will never be found coexisting in the same geographical area with any type of dragon. If a dragon should enter a behir's territory, the behir will do everything it can to drive the dragon out. If the behir fails in this task, it will move off to find a new home. A behir will never knowingly enter the territory of a dragon.
Behir are useful to mages, priests, and alchemists for a number of concoctions. The horns of a behir can be used to brew the ink necessary to inscribe a lightning bolt scroll, and the sharp talons can likewise be used by a cleric to make the ink for a neutralize poison scroll. The heart of the behir is one of the more common ingredients for ink for a protection from poison scroll.
As behir sometimes swallow prey whole, there is a 10% chance that there will be some small items of value inside the monster. More often than not (60%) these will be gems (10 x Q). Otherwise, there is a 30% chance that there will be from 1-8 pieces of jewelry and a 10% chance that a single small magical object of an indegistible nature may be found. Such objects are never found in a behir's lair, because the creature expels this waste and buries it elsewhere.
The scales are valued for their hardness and color, and are worth up to 500 gp to an armorer who can use them to fashion a highly ornate set of scale mail armor.