Ahuizotl

Dog-sized, slick-furred, with monkey hands and a fifth hand on the end of its tail. It lies in the reeds and cries like a child in the water until somebody wades in after the sound. What comes back to the bank three days later is intact except for the eyes, the teeth and the fingernails, which is how everyone knows what took them, and which is why the bodies are treated as a matter for the priests rather than the constable.

Tail Hand: bludgeoning, melee 10 ft, +4 to hit, 2d6+3, and on a hit the target is dragged into adjacent water. Bite: piercing, melee 5 ft, +4 to hit, 2d8+3, its second attack each round, used once something is in the water with it. Weeping: 60 ft, it imitates a child or a familiar voice in distress. Save Wis Mind, fail save roll 1d6+2 psychic and the target moves toward the sound and into the water. Cooldown 2 rounds.

Takes Only Three Things: it drowns rather than eats, and takes the eyes, teeth and nails afterward. A body recovered before it has finished can still be revived; a body it has finished with cannot be raised at all. Of the Reeds: in water it cannot be surprised and attacks at Advantage. On dry land it is slow, unhappy and beatable.