Ruby Slippers

The Ruby Slippers are a pair of magical shoes that originated from the land of Oz. They were originally owned by the Wicked Witch of the East, who used their power to terrorize Oz. They gained their name by virtue of their ruby red color. After the death of the witch, they fell into the possession of Dorothy, who kept them for years without realizing their true potential for use against other witches from Oz.

History
As later noted by Dorothy, the Ruby Slippers were originally owned by another Wicked Witch besides the one they faced in Slumber Party, in this case the Wicked Witch of the East. Upon the witch's death, Dorothy inherited her magical footwear, though she never displayed any inclination to put them on her own feet given her queasiness about wearing a dead woman's shoes. Dorothy did however keep the shoes as a trophy to remember her triumph over the Wicked Witch of the East, not realizing their potential to combat other Wicked Witches in Oz.

When Dorothy and the Wicked Witch of the West are accidentally released from their suspended animation by the Winchesters and Charlie Bradbury, Dorothy relates the story of how they originally ended up in that way and how she nor the Men of Letters were able to find a way to kill the Wicked Witch. Some time later, after berating her father's (L. Frank Baum) written stories about her and subsequently being tipped off by Charlie Bradbury that he had written them to leave her clues as to how to deal with the witch, Dorothy realizes that the Ruby Slippers (which are imbued with the magic of Oz) are capable of killing the Wicked Witch. The two proceed to the bunker's garage, where Dorothy retrieves the slippers from her motorcycle. However, soon after this, a possessed Sam and Dean confront the pair under the control of the Wicked Witch. Dorothy tosses the slippers to Charlie and instructs her to kill the witch with them while she holds Sam and Dean off. Charlie successfully locates the Wicked Witch and stabs her with the magical shoes, killing her and ending her threat.