Crocodilian

Crocodilian
Large monstrosity (bloodsucker), chaotic evil
—Armor Class 14 (natural armor)
Hit Points 102 (12d10 + 36)
Speed
— 30 ft., swim 50 ft.
STR DEX CON INT WIS CHA
—19 (+4) 13 (+1) 17 (+3) 2 (-4) 12 (+1) 6 (-2)
Saving Throws Str +7, Con +6
Skills Athletics +7, Perception +4, Stealth +4
Senses darkvision 60 ft. passive Perception 14
Languages -
Challenge
—5 (1,800 XP)
Apex Predator. Any hit by a bite attack the Crocodilian scores
against a target, that is surprised or unable to see it, is a
critical hit.
Hold Breath. The Crocodilian can hold its breath for 1 hour.
Marsh Prowler. The Crocodilian has advantage on Dexterity
(Stealth) checks when it hides in murky or swampy waters.
Actions
Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one
target. Hit: 23 (3d12 + 4) piercing damage. The target must
succeed on a DC 15 Strength saving throw or is grappled by
the Crocodilian, escape DC 15. Until the grapple ends, the
Crocodilian can’t bite another target.
Swarming Corruption (Recharge 4-6). The Crocodilian
unleashes its a parasitic swarm of mosquitos that fills a
20-foot-radius around the Crocodilian. Every creature except
for the Crocodilian in the area must make a DC 14 Dexterity
saving throw. On a failed save the creature takes 9 (2d8)
piercing damage and on a successful saving throw only half as
much. Additionaly until the beginning of the Crocodilian’s next
turn the area is heavily obscured by the swarming mosquitos.
Submerge (1/Short Rest). Can only be used when the
Crocodilian is within a body of water. It hides and regains 13
(3d8) hit points.