Bite

Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 21 (3d10+5) piercing damage. On a hit the shark can make a second bite attack as a bonus action.

Tail

Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 15 (3d6+5) bludgeoning damage and the shark can swim 20 feet without provoking opportunity attacks.