Behir Stormstrider

Ride the Lightning. While the Behir's Lightning Breath is charged, it has a flying speed equal to its climbing speed and can hover.

Voltaic Link. While a friendly creature is mounted on the behir, the two can communicate telepathically, and the rider gains resistance to lightning damage.

Multiattack. Makes two attacks: one with its bite and one to constrict.

Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 3d10+6 piercing damage.

Constrict. Melee Weapon Attack: +10 to hit, reach 5 ft., one Large or smaller creature. Hit: 2d10+6 bludgeoning damage plus 2d10+6 slashing damage. The target is grappled (Escape DC 16 Strength check) if the behir isn't already constricting a creature, and the target is restrained until this grapple ends.

Lightning Breath(Recharge 5-6). Exhales a line of lightning that is 20 ft. long and 5 ft. wide. Each creature in that line must make a DC 16 Dex Save, taking 12d10 lightning damage on a failed save, or half as much damage on a successful one.

Swallow. Makes one bite attack against a medium or smaller target it is grappling. If the attack hits, the target is also swallowed, and the grapple ends. While swallowed, the target is blinded and restrained, it has total cover against attacks and other effects outside the behir, and it takes 6d6 acid damage at the start of each of the behir's turns. A behir can only have one target swallowed at a time.

If the behir takes 30 damage or more on a single turn from the swallowed creature, the behir must succeed on a DC 14 Con Save at the end of that turn or regurgitate the creature, which falls prone in a space within 10 ft. of the behir. If the behir dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 15 ft. of movement, exiting prone.

Voltaic Link. While Voltaic Link is active, the Behir can expand its lightning breath to cause a willing creature of its choice that it can see within 120 ft. of it to teleport onto its back, mounting it.