Cannon Lobster

Amphibious. The lobster can breathe air and water.

Claw. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) bludgeoning damage, and the target is grappled (escape DC 11). The crab has two claws, each of which can grapple only one target

Bubble Cannon (Recharge 5-6). A bubble shoots out of the lobster's larger claw toward a point within 150 feet from the lobster, where it will then explode. Each creature in a 20-foot-radius sphere centered on that point must make a DC13 Dexterity saving throw. A target takes 2d6 thunder damage and 2d6 fire damage on a failed save, or half as much damage on a successful one. This action cannot be used if both claws are grappling creatures.