Typing "Halfling" spawns a small, barefoot man with curly black hair. He is friendly and is even found in one of the puzzles, buried alive in a crate. Dwarves, Elves, and Wizards will automatically protect Halfings, and Halflings themselves will protect Rings. A Halfling will lock like the original munchkin from The Wizard of Oz.
Obviously, this is a reference to Lord of the Rings. Halfling is another name for hobbit, and the hobbit in question is Frodo Baggins.