Hold Breath. The plesiosaurus can hold its breath for 1 hour.
Bite. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit:14 (3d6 + 4) piercing damage.
A plesiosaurus is a marine dinosaur whose compact body is driven by powerful flippers. Predatory and aggressive, it attacks any creature it encounters. Its flexible neck accounts for a third of its total length, letting it twist in any direction to deliver a powerful bite.