Were-worms

"Tell me what you want done, and I will try it, if I have to walk from here to the East of East and fight the wild Were-worms in the Last Desert."

- Bilbo Baggins, The Hobbit

Were-worms were most likely imaginary or mythical creatures told of in the stories of hobbits. But then again, most stories have some grain of truth in them. The were-worms were supposedly terrible monsters that made their home in the Last Desert very far east of the Shire. For a hobbit to declare himself prepared to fight ware-worms was a sort of proverbial way of saying that he was ready to do anything.