Fire Bar

Firebars are rotating rods made of fireballs first appearing in Super Mario Bros.. They are found in numerous titles throughout the Mario series. They are generally found in fortresses and act as dangerous obstacles that Mario must avoid in order to reach the goal.

Firebars were also given notable appearances in certain castles of Super Mario World 2: Yoshi's Island, which depicted them as swinging three-dimensionally. A three-dimensional Firebar depicted with eyes also appeared in Waluigi Stadium and Bowser's Castle course of Mario Kart: Double Dash!!.

Super Mario Bros.
They made their first debut in Super Mario Bros.. Although they are not a living enemy, they go swinging around trying to hurt Mario or Luigi. In later games, they were replaced with similar-acting enemies such as Roto-Discs and Ball 'n' Chains.

Super Mario 64
In Super Mario 64, they appeared for the first time in full 3D. They only appeared in Lethal Lava Land.

Paper Mario
In Paper Mario, the Firebars reappeared in Koopa Bros. Fortress and Mt. Lavalava; this time they swing sideways. They also swing either clockwise or counter-clockwise, if Mario touches one; he loses some HP. Jumping over one of these Firebars causes it to swing faster. If Mario dodges one 10 times, it will vanish and drop a number of coins. This is the only appearance that Firebars can be defeated.

Super Mario Galaxy
In Super Mario Galaxy, they appear in Bowser's Star Reactor and Bowser's Galaxy Reactor.

Super Mario Galaxy 2
In Super Mario Galaxy 2, they are used in the same way as in Super Mario Galaxy. They mainly appear in Bowser Jr.'s Fiery Flotilla, Bowser's Gravity Gauntlet, Slipsand Galaxy and Bowser's Galaxy Generator. Also of note is that Firebars are used during the boss fight with Bowser Jr.'s Boomsday Machine, in which they are integrated into the Boomsday Machine.

Trivia

 * Firebars were featured as collectible items in Animal Crossing: Wild World and Animal Crossing: City Folk. When it is set down, it plays the castle music of Super Mario Bros. while the Firebar spins.
 * In The Legend Of Zelda: A Link to the Past, Firebars spin on the ground.
 * According to Satoru Iwata, "...firebars, which appear in Super Mario Bros., had also been used early on in development of The Legend of Zelda: A Link to the Past."
 * Firebars are the only enemies in Super Mario Bros. to not return in Super Mario Bros. 3