Candy Rings are circular projectiles that Wendy O. Koopa can shoot from her Magic Scepter. They are named for the fact that they are colored in red and white stripes, similar to a candy cane.
Candy Rings were first seen in Super Mario Bros. 3, where Wendy attempts to shoot them at Mario. They later reappear in Mario & Luigi: Superstar Saga, where they were able to expand and squeeze Mario and Luigi.