Fire Bar

Firebars are fireball sticks found in fortresses in Super Mario Bros. Although 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.

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 enough times, it will vanish and drop a number of coins.

They were the only enemy of the original Super Mario Bros. to not be featured again in Super Mario Bros. 3. They appear in later Mario games such as New Super Mario Bros., Paper Mario: The Thousand-Year Door, Yoshi's Island DS, and Super Paper Mario. They were also given notable appearances in certain castles of Super Mario World 2: Yoshi's Island, which depicted them as swinging three-dimensionally; a Firebar working on similar 3D mechanics also appeared in the Bowser's Castle racecourse of Mario Kart: Double Dash!!.

Super Paper Mario
"That's a Fire Bar. Don't touch it, or you'll get burned..."

Trivia

 * Firebars were featured as collectible items in Animal Crossing: Wild World.