Been a while since I did some of these.
Marsh Cry Mantis
Forced to a diet of elves it generates, locust-like, remarkable original symphonies of startling beauty from its leg-bows. A walking concerto. Music is so beautiful that you have to fail a wisdom test each round in order to hit it.
A network of arteries and veins moving in the form of a man, as if a giant had been flayed of all flesh leaving only the tracery of blood. Move and stills as its great heart beats. Still for one round and them moves in another. Attack it and the living blood creeps around you like tentacles and the blue veins try to gouge out your eyes and pull off your limbs. But only one each round. Arteries grasp one round, veins kill the next. Grasp and damage. On and off, on and off.
An gang of Mandrills that follow you and rips the shit out of you from a distance. They will track you in the wilderness and observe you. Wis test to detect. The next time you see them they will act out in mime your latest mistake you made and make you look like a proper tit. Then they throw their shit at you. They will do this until you lose it and go after them. In which case you will be walking into a trap. They dig pits, bend branches, collect snakes, whatever seems appropriate.
Fat black flies with the heads of blind weeping children. Beg for you to kill them as they go after your soft tissues. In a little high-pitched fly voice, like a soft whine on the edge of your perception going 'kiiiiiillll meeeeee pleeeeease'