Cowboy Gunshrimp

Amphibious. The cowboy gunshrimp can breath both air and water.

Limited Ammunition. Each claw cannon carried by the cowboy gunshrimp has 6 rounds in it, and the cowboy gunshrimp has 1d12 rounds on its gun belt. Reloading a single claw cannon takes an action (and a bonus action to stow the other gun).

Quick Draw. The cowboy gunshrimp can draw its claw cannons as a free action, but cannot do so if it stowed the gun that round. Stowing a claw cannon is a bonus action.

Multiattack. The cowboy gunshrimp can make either two claw attacks or two claw cannon attacks when it spends its action to Attack.

Claw. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 2) bludgeoning damage. 

Claw Cannon. RangedWeapon Attack: +8 to hit, range 80/320 ft., 1 target. Hit: 20 (3d10 + 4) bludgeoning damage.

Fan The Hammer (Recharge 5-6). The cowboy gunshrimp stows a claw cannon (using its bonus action) and fires 1d4+1 (minimum 1, no more than the shots remaining in the respective claw cannon) shots from the claw cannon. The attacks are made at a penalty equal to the number of shots fired.

Fast On The Draw. If a hostile creature makes a ranged attack against the cowboy gunshrimp while in range of the claw cannons, the cowboy gunshrimp can use its reaction to make a ranged attack with the claw cannons. The target and the gunshrimp make opposed Dexterity checks, with the winner resolving their attack first.