Bite

Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 29 (4d10 + 7) piercing damage and the target is grappled (escape DC 18).

Swallow

The devil shark makes one bite attack against a Large or smaller target it is grappling. If the attack hits, the target is also swallowed, and the grapple ends. While swallowed, the target is blinded and restrained, it has total cover against attacks and other effects outside the devil shark, and it takes 21 (6d6) acid damage at the start of each of the devil shark's turns. A devil shark can have two Large, four Medium, or six Small creatures swallowed at a time. If the devil shark takes 30 damage or more on a single turn from a swallowed creature, the devil shark must succeed on a DC 18 Constitution saving throw or regurgitate all swallowed creatures, which fall prone within 10 feet of the devil shark. If the devil shark dies, a swallowed creature is no longer restrained by it and can escape by using 20 feet of movement, exiting prone.

Freezing Breath (Recharge 5-6)

The devil shark exhales a 60-foot cone of supernaturally cold water. Each creature in that area must make a DC 18 Constitution saving throw. On a failed save, a target takes 54 (12d8) cold damage and is pushed 20 feet away from the devil shark. On a success, a target takes half the damage but isn't pushed.