Caedus Acidus

Hold Breath. The C.A. can hold its breath for 45 minutes.

Keen Sight and Smell. The C.A. has advantage on Wisdom (Perception) checks that rely on sight or smell.

Standing Leap. The C.A.'s long jump is up to 30 feet and its high jump is up to 15 feet, with or without a running start.

Multiattack. The C.A. makes four attacks: one with its bite, one with its tail and two with its claws.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 16 (2d10 + 5) piercing damage and must make a DC 13 Constitution saving throw or take 5 (2d4)poison damage on a failed save. The target is also grappled (escape DC 16). Until this grapple ends, the target is restrained, and the C.A. can't bite another target.

Tail. Melee Weapon Attack: +8 to hit, reach 10 ft., one target not grappled by the C.A. Hit: 11 (1d10 + 5) piercing damage. If the target is a creature, it must succeed on a DC 16 Strength saving throw or be knocked prone.

Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage and 3 (1d6) acid damage 

Acid Spit (Recharge 5–6). The C.A. exhales acid goo in a 15-foot cone. Each creature in that area must make a DC 15 Dexterity saving throw, taking 25 (10d4) acid damage on a failed save, or half as much damage on a successful one.