Fire Chain

Fire Rings are spinning fireballs formed in a ring shape that only appeared in the Mario Kart series. Similar to Fire Bars, Fire Rings serve as obstacles in all games in which they appear, and their rotating movement is similar to that of the Circling Boo Buddies.

Mario Kart: Double Dash!!
Fire Rings first appear in Mario Kart: Double Dash!!. They appeared in Waluigi Stadium and Wario Colosseum alongside normal Fire Bars, where they burn any racer that comes in contact with it.

Mario Kart DS
Fire Rings reappeared in Mario Kart DS, where they were found in Wario Stadium. They play the same role trying to burn any racer to slow them down.

Mario Kart 8
Fire Bars reappear in Mario Kart 8, where they only appeared in the Wario Stadium retro course. Here they are once again the main obstacle along with normal Fire Bars.