| Hit Dice: | 9d10+45 (94 hp) |
| Initiative: | +1 |
| Speed: | 40 ft. (8 squares), climb 15 ft. |
| Armor Class: | 20 (–2 size, +1 Dex, +11 natural), touch 9, flat-footed 19 |
| Base Attack/Grapple: | +9/+25 |
| Attack: | Bite +15 melee (2d4+12) |
| Full Attack: | Bite +15 melee (2d4+12) |
| Space/Reach: | 15 ft./10 ft. |
| Special Attacks: | Breath weapon, constrict 2d8+8, improved grab, rake 1d4+4, swallow whole |
| Special Qualities: | Darkvision 60 ft., immunity to electricity, low-light vision, serpentine, scent |
| Saves: | Fort +11, Ref +7, Will +5 |
| Abilities: | Str 26, Dex 13, Con 21, Int 7, Wis 14, Cha 12 |
| Skills: | Climb +16, Hide +5, Listen +4, Spot +4, Survival +2; racial bonuses |
| Feats: | Alertness, Cleave, Power Attack, Track |
| Environment: | Warm hills |
| Organization: | Solitary or pair |
| Challenge Rating: | 8 |
| Treasure: | Standard |
| Alignment: | Often neutral |
| Advancement: | 10–13 HD (Huge); 14–27 HD (Gargantuan) |
| Level Adjustment: | — |
At first the creature appears as a huge armored snake, slithering across the ground at great speed. Then, without slowing, it unfolds a dozen legs from its serpentine body and runs forward to strike.
The behir is a serpentine monster that can slither like a snake or use its dozen legs to move with considerable speed. A behir is about 40 feet long and weighs about 4,000 pounds. It can fold its limbs close to its long, narrow body and slither in snake fashion if it desires. The coloration of behirs 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 but are actually used for preening the creature’s scales, not for fighting.
Behirs are never friendly with dragonkind and won’t coexist with any type of dragon. If a dragon enters a behir’s territory, the behir does everything it can to drive the dragon out. If the behir fails, it moves off to find a new home. A behir never knowingly enters the territory of a dragon.
Behirs speak Common.
A behir usually bites and grabs its prey first, then either swallows or constricts the opponent. It can employ its claws only against foes caught in its coils. If beset by a large number of foes, it uses its breath weapon.
Breath Weapon (Su): 20-foot line, once every 10 rounds, damage 7d6 electricity, Reflex DC 19 half. The save DC is Constitution-based.
Constrict (Ex): A behir deals 2d8+8 points of damage with a successful grapple check. It can make six rake attacks against a grappled foe as well.
Improved Grab (Ex): To use this ability, a behir must hit a creature of any size with its bite attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it it establishes a hold and can attempt to constrict the opponent or swallow the opponent in the following round.
Rake (Ex): Six claws, attack bonus +15 melee, damage 1d4+4.
Swallow Whole (Ex): A behir can try to swallow a grabbed Medium or smaller opponent by making a successful grapple check. A behir that swallows an opponent can use its Cleave feat to bite and grab another opponent.
A swallowed creature takes 2d8+8 points of bludgeoning damage and 8 points of acid damage per round from the behir’s gizzard. See Swallow Whole for escape methods. A behir’s gizzard has an AC of 15 and 25 hp.
A behir’s gizzard can hold 2 Medium, 8 Small, 32 Tiny, or 128 Diminutive or smaller opponents.
Skills: Behirs have a +8 racial bonus on Climb checks and can always choose to take 10 on Climb checks, even if rushed or threatened.
Source: Monster Manual (version 3.5), page 25. Added the serpentine special quality, which includes the deleted “can’t be tripped” one. Changed the Swallow Whole escape method.