Ghest

Armor Class 14 · Hit Points 104 (11d12 + 33) · Speed 20 ft., swim 60 ft.

Ambusher (Trait). In the first round of a combat, the ghest has advantage on attack rolls against any creature it surprised.

Hold Breath (Trait). The ghest can hold its breath for 30 minutes.

Multiattack (Action). The ghest can make two attacks: one with its bite and one with its claws.

Bite (Action). Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 21 (3d10 + 5) kinetic damage and the target is grappled (escape DC 16). Until this grapple ends, the target is restrained, and the ghest can't bite another target.

Claws (Action). Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) kinetic damage.

Swallow (Action). If the ghest takes 25 damage or more on a single turn from a creature inside it, the ghest must succeed on a DC 14 Constitution saving throw at the end of that turn or regurgitate the swallowed creatures, which fall prone in a space within 10 feet of the ghest. If the ghest dies, the swallowed creatures are no longer restrained by it and can escape from the corpse using 5 feet of movement, exiting prone. The ghest makes one bite attack against a Medium or smaller target it is grappling. If the attack hits, the target is swallowed, and the grapple ends. The swallowed target is blinded and restrained, it has total cover against attacks and other effects outside the ghest, and it takes 10 (3d6) acid damage at the start of each of the ghest's turns. The ghest can have only one target swallowed at a time.