Crabsta

Amphibious. The crabsta can breathe air and water.

Pack Tactics. The crabsta has advantage on an attack roll against a creature if at least one of the crabsta's allies is within 5 feet of the creature and the ally isn't incapacitated.

Gangsta Run. As a bonus action, the crabsta can make a DC 15 Dexterity (Acrobatics) check. If it succeeds, difficult terrain doesn’t cost him extra movement until the end of the current turn and it does not provoke opportunity attacks.

Multiattack. The crabsta makes one claw attack and one flintlock pistol attack.

Claw. Melee Weapon Attack: +0 to hit, reach 5 ft., one target. Hit: 2 bludgeoning damage.

Flintlock Pistol. Melee Weapon Attack: +4 to hit, range 80/320 ft., one target. Hit: 5 (1d6 + 2) bludgeoning damage. Miss or hit, the recoil of the pistol then flings the crab 10 feet away from the target in a straight line.