According to a story dating back to Aesop, beavers were hunted for their testicles. Somehow, the beavers understood this and so when they realised that escape was impossible, they made a last desperate manoeuvre. Bending themselves double, they would bite off their own testicles; then the hunters could take the testicles and leave the beavers alone.
An exceptionally flexible beaver attempting to escape hunters. Image from the British Library, via Medieval Bestiary.
Of course, this is total nonsense. Much of the science of the ancients was built on the same principles as story-telling, the ideas of what related to what often seemed to be built on the same reasoning that would make sense in a story. As when a knight in a story finds a sword with a snake inscribed on the blade and concludes that either it will be poisoned or will be deadly to snakes, so too did the ancients see that the seeds from the Echium vulgare resembled snake heads and concluded that it could cure snake-bite.
In this case, it’s a moral tale, related to the bible saying that “if your right hand causes you to sin, cut it off”, or the story of Saint Lucy cutting out her eyes to dissuade an admirer.
This would make quite a scene in a game: the characters are hunting an animal for some part of its body (if the players are too squeamish to hunt for testicles, perhaps the horn, mane, or tail?). At some point in the chase, the characters find the animal standing at the other side of a clearing just finishing the task of tearing off the very part that they wish to get. The animal looks at the characters as if to say “there, you got what you came for, now leave me alone” and walks off into the wood. What would they make of that? Is it really just an animal if it can make such a decision? And what might it be hiding in the forest if it’s prepared to cut off parts of its own body protect it?