Crabbeard

Limited Amphibiousness. Crabbeard can breathe air and water, but they need to be submerged once every 24 hours to avoid suffocating.

Aggressive. As a bonus action, Crabbeard can move up to their speed toward a hostile creature that they can see.

Point Blank. Crabbeard's pistol attack automatically crits when it hits a target they're grappling.

Multiattack. Crabbeard makes a claw attack and a pistol or grenade attack.

Claw. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 8 (1d6 + 5) bludgeoning damage and the target is grappled (escape DC 15). Until this grapple ends, Crabbeard  can automatically hit the target with its claw, and Crabbeard can’t make attacks with that claw against other targets. Crabbeard  has only one claw, which can grapple only one target.

Pistol. Ranged Weapon Attack: +4 to hit, range 30/90 ft., one target. Hit: 7 (1d10 + 2) piercing damage. Reloading takes a bonus action.

Fragmentation Grenade (3/day). Crabbeard throws a grenade up to 60 feet. Each creature within 20 feet of the grenade’s detonation must make a DC 15 Dexterity saving throw, taking 17 (5d6) piercing damage on a failed save, or half as much damage on a successful one.