Bone-tip Scuttler

Multiattack. The Scuttler makes three Rib Jab attacks, or two Corrosive Spew attacks. If it is currently grappling a creature with Engulfing Bite, it can only use the Consume attack.

Rib Jab. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit:  18 (3d6+6) piercing damage.

Corrosive Spew. Ranged Weapon Attack: +9 to hit, reach 30 ft., one target. Hit: 13 (1d12+6) acid damage and 13 (1d12+6) necrotic damage.

Engulfing Bite. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 17 (2d10 + 5) piercing damage. If the target is a Medium or smaller creature, it is grappled (escape DC 17). Until this grapple ends, the target is restrained, and the Scuttler can't bite another target.

Consume. The Scuttler makes one bite attack against a Medium or smaller creature it is grappling. If the attack hits, that creature takes the bite's damage and is swallowed, and the grapple ends. While swallowed, the creature is blinded and restrained, it has total cover against attacks and other effects outside the Scuttler, and it takes 12 (3d6) acid damage and 12 (3d6) necrotic damage at the start of each of the Scuttler's turns. The Scuttler heals for the amount of necrotic damage dealt.

If the Scuttler takes 25 damage or more in a single instance of damage, the Scuttler must succeed on a DC 17 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 5 feet of the Scuttler. If the Scuttler dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 15 feet of movement, exiting prone.