Fire Chain

Fire Chains are spinning fireballs formed in a ring shape that originally appeared in the Mario Kart series. Similar to Fire Bars, Fire Chains 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 Chains 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 Chains 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 Wii
Fire Chains reappear in Mario Kart Wii, where they found once again in the Waluigi Stadium retro course, and in Bowser's Castle where they are made up of three fireballs each.

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

Super Mario Galaxy 2
Fire Chains also appeared in Super Mario Galaxy 2. They appeared in Bowser's Lava Lair, in the starting planet, and the fireball planet, and the Slipsand Galaxy in its starting planet. They behave the way they did in the Mario Kart games, though sometimes, they go around planets instead of circling in the air.

Super Mario Run
Fire Chains return in Super Mario Run, except with an appearance of a complete "ring of fire" rather than separate sets of fireballs. They appear only in the level Rings of Fire!.