Baspsylisk

Petrifying Gaze. If a creature starts its turn within 30 feet of the basilisk and the two of them can see each other, the baspsylisk can force the creature to make a DC 12 Constitution saving throw if the baspsylisk isn't incapacitated. On a failed save, the creature magically begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified until freed by the greater restoration spell or other magic.

A creature that isn't surprised can avert its eyes to avoid the saving throw at the start of its turn. If it does so, it can't see the baspsylisk until the start of its next turn, when it can avert its eyes again.

If it looks at the baspsylisk in the meantime, it must immediately make the save. If the baspsylisk sees its reflection within 30 feet of it in bright light, it mistakes itself for a rival and targets itself with its gaze.

Multiattack. The baspsylisk makes two tentacle attacks and one bite. Up to two tentacle attacks can be replaced by Baleful Constriction.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) piercing damage plus 7 (2d6) poison damage.

Tentacle. Melee Weapon Attack: +6 to hit, reach 15 ft., one target. Hit: 7 (1d6 + 4) bludgeoning damage. The target is grappled (escape DC 12) if it is a Large or smaller creature. Until this grapple ends, the baspsylisk can’t use the same tentacle on another target. The baspsylisk has two tentacles.

Baleful Constriction. One creature grappled by a tentacle of the baspsylisk must make a DC 11 Strength saving throw. On a failed save, the target takes 5 (1d8) necrotic damage, and has disadvantage against all saving throws until the baspsylisk's next turn.