Tatzelwurm

Poisonous Blood. Its blood is as toxic as its bite. When it takes piercing or slashing each creature within 5 ft. of it: DC 14 Con save or take 5 (2d4) poison. A creature that consumes flesh of tatzelwurm: DC 14 Con save or poisoned 8 hrs.

Pounce. If it moves 20'+ straight to creature and then hits it with Claw on same turn target knocked prone (DC 14 Str negates). If target prone wurm can make one Bite vs. it as a bonus action.

Multiattack. One Bite attack and two Claw attacks.

Bite. Melee Weapon Attack: +6 to hit, 5 ft., one target, 10 (2d6+3) piercing damage + 5 (2d4) poison.

Claw. Melee Weapon Attack: +6 to hit, 5 ft., one target, 6 (1d4+3) slashing damage.

Poisonous Breath (Recharge 6). Exhales a cloud of poisonous vapor in a 15 ft. cone. Each creature in that area: 21 (6d6) poison and is poisoned for 1 min (DC 14 Con half damag not poisoned). A poisoned creature can re-save at end of each of its turns success ends effect on itself.

Move. Up to half its speed with o provoking opportunity attacks.

Angry Hiss (2). Each creature within 30' of it: frightened until the end of its next turn (DC 13 Wis negates).

Tail Slap (2). Swings its tail in a wide arc around it. Each creature within 10 ft. knocked prone (DC 14 Str negates).