n medium aquatic elemental water 

Perception +8; darkvision

Skills Athletics +10, Stealth +11, Survival +8

Str +3 Dex +2 Con +2 Int -4 Wis +1 Cha +0

AC  19; Fort +9, Ref +11, Will +6

HP 45; Immunities bleed, poison, sleep; Resistances fire 5

Speed 15 feet, swim 50 feet

Melee [>] jaws +11, Damage 1d12 + 7 piercing plus Grab

Deep Plunge [>] The brine shark dives straight down into the water, swimming up to 100 feet in a straight vertical line. It can use this ability while grabbing a creature.

Grab [>] When the brine shark succeeds at its jaws Strike, it can use this action immediately after to automatically give the target the grabbed condition until the end of its next turn.

Beginner Box, page 62.