Multiattack

One Fanged Tentacles and two Slams or it makes three Slams. It can replace two Slams with Chomp.

Fanged Tentacles

Melee Weapon Attack: +7 to hit, 10 ft., one target, 9 (2d4+4) piercing damage + 9 (2d8) poison and target is grappled (escape DC 15). Until the grapple ends the target is restrained and mortifera can't use its Fanged Tentacles on another.

Slam

Melee Weapon Attack: +7 to hit, 5 ft., one target, 10 (1d12+4) bludgeoning damage.

Chomp

One creature grappled by mortifera is pulled up to 5 ft. to mortifera's central maw which chomps on creature. Target: 10 (3d6) piercing damage and 13 (3d8) poison (DC 15 Str half).

Poison Spray (Recharge 5-6)

Sprays poison from its central maw in a 30' cone. Each creature in that area: 27 (6d8) poison (DC 15 Dex half).