Armor Class 12 (natural armor)
Hit Points 22 (4d8 + 4)
Speed swim 40 ft.
Skills Perception +2
Senses blindsight 30 ft., passive Perception 12
Languages —
Challenge 1/2
Pack Tactics. The shark has advantage on an attack roll against a creature if at least one of the shark's allies is within 5 feet of the creature and the ally isn't incapacitated.
Water Breathing. The shark can breathe only underwater.
Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 6 (1d8 + 2) piercing damage.
Monster Manual (2014), p. 336