Large Beast, unaligned
Armor Class 13 (natural armor)
Hit Points 68 (8d10+24)
Speed swim +40, walk +20
Challenge 2
Skills stealth +4, perception +3
Senses passive Perception 13
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.
Source: 5e Core Rules · OGL/Open