How can Frodo be a foil for himself? Well, just as our favorite little guy is both a protagonist and an antagonist in Return of the King, so the opposite sides of his personality help to highlight each other. As Frodo succumbs to the evil power of the Ring, we remember the old Frodo—the fun one, the steadfast Frodo, the good, genuine hobbit. And when he finally gives in, and tries to take the Ring for himself, we can't help but let out a little yelp. Don't do it Frodo! You're good inside! Alas, Frodo is Frodo's own worst enemy. Foil, indeed.