Hand Tree

Far off in the World Under the Unblinking Eyes lives a curious lifeform that resembles nothing short of a human hand. They grow like fruit from equally hand-like "trees", but from then on live their lives more like a terrestrial animal -- until, that is, when they fully mature, and their handy faces drop off, bury themselves underground, and sprout hand trees from their fingertips, starting the cycle anew.

Each tree produces up to 5 offspring each year, meaning a healthy mature individual hand critter can have 25 children in one go. Offspring hands usually have the same "handedness" as their parent, though thumbs often produce the opposite and sometimes opposites happen for no reason at all. Not that it matters, lefties and righties do just as well as each other.

The former bodies of mature hand critters generally die soon after their heads drop off, but a rare few manage to survive and develop an unstoppable murderous hatred of their former head's offspring.