Whip

The Whip is an item in Spirit Tracks, obtained in the Ocean Temple. Its main use is to swing from poles similar to what the Grappling Hook from Wind Waker and for puzzles found in certain dungeons that require the transfer of certain swords. It does have a use as a weapon as it can attack certain ChuChus that Link could not attack with his sword alone and it can take the shields and armor from certain enemies.

Trivia

 * The Whip seems reminiscent of the Rope, a snake like enemy appearing in early Zelda games. It also shares similarities with the Rope Snake, an item that appears in the Nintendo game Mother 3, as well in Super Smash Bros. Brawl, used by Lucas.