Add a way to undo polymorph

[Arborinus]

I always thought Polymorph was a temporary thing in other games, but it seems in D&D it was usually permanent? I can see why people like to be critters but I don't like being permanently weakened all round without being able to be cloned. What if, after three minutes or something, a polymorphed player gets a "Return to Human" verb that changes them into a (naked) human and gives a short stun.