Dedede Brooch
The Dedede Brooch (Japanese デデデの時限スイッチ) is a non-gameplay item originating from the Subspace Emissary mode in Super Smash Bros. Brawl. It appears to be an adhesive, golden brooch with an imprint of Dedede's face on it. The brooches are used to revive the wearer of their trophy state, activating after a certain period of time has passed.
King Dedede learned about Tabuu's motive, and about the attack that would turn everyone into trophies, the Off Waves, and created these brooches so that the fighters would change back from their trophy states. They were placed on Luigi (whom he ambushed), Ness, and Zelda/Peach (although it seems he intended to use the third one for himself), after stealing their trophies from Wario. After Zelda/Peach was taken from King Dedede by Bowser in a surprise ambush, Kirby found the brooch and swallowed it, so he gained the benefits of it as well when he was turned into a trophy in Subspace. Had King Dedede never made these, then everyone would be doomed, or Sonic, and to a lesser extent, Jigglypuff, Toon Link, or Wolf, would have to save everyone, as they were not caught in Tabuu's Off Waves.