Amphibious. The Abyssal Fishmonger can breathe air and water.

Multiattack. The Abyssal Fishmonger makes two attacks: one with its claw and one with its bite.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) piercing damage, and the target must make a DC 16 Constitution saving throw or be poisoned for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on a success.

Claw. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 11 (2d6 + 4) piercing damage, and the target must succeed on a DC 16 Strength saving throw or be pulled 5 feet toward the Abyssal Fishmonger.

Harmonic Resonance (Recharge 5-6). The Abyssal Fishmonger releases an eerie hum, creating a 30-foot-radius sphere of supernatural sound. Each creature within that area must make a DC 16 Wisdom saving throw or take 22 (4d10) psychic damage and become frightened for 1 minute. A frightened creature can repeat the saving throw at the end of each of its turns, ending the effect on a success.

Shallow Step. If the Abyssal Fishmonger is in water, it can use its bonus action to teleport to another body of water within 60 ft. Both water sources must be big enough for the Abyssal Fishmonger to fit through.