Magical ball

Magical balls, also referred to as beach balls, circus balls, and rubber balls, are balls with star patterns on them that Lemmy Koopa can shoot from his magic wand. They are usually small, but they can come in large varieties as well. Although they are usually found in fights with Lemmy, sometimes they appear as obstacles in his castles.

Super Mario Bros. 3
Magical balls are first seen in Super Mario Bros. 3, where Lemmy attempts to shoot them at Mario (or Luigi) while balancing on one himself. They bounce on the floor, changing direction when they bump into a wall. If Mario touches one, he takes damage, unlike in future games; however, jumping on one merely bounces him upwards, while causing the ball to flash between colors and drop to the floor.

Super Mario World
Fiery versions of magical balls appear in Super Mario World, where they are instead used by Iggy and Larry. They summon them out from their shells' neckline after ducking their heads inside, then roll them at Mario. Due to being fire, they cannot be jumped on, though they can be destroyed by sliding into them, displaying a glitched sprite.

New Super Mario Bros. Wii
Circus balls return in New Super Mario Bros. Wii, but instead of hurting Mario if they touch him, as in Super Mario Bros. 3, they instead simply bump him, which can push him off the edge. Circus balls also changed colors from green with orange stars to yellow with orange stars. Circus balls appear in World 3-Tower and World 3-Castle, where Lemmy himself is fought. Mario is supposed to jump off the balls to reach Lemmy, due to the icy floor. In the Castle fight, Lemmy has Kamek tripling the size of his ball, so he can bounce on it to move around. The balls also appear in the World 3-Castle level itself, bouncing above spikes leading to a Star Coin.

New Super Mario Bros. 2
Rubber balls reappear in World Flower-Castle in New Super Mario Bros. 2, appearing in the level next to one of the Star Coins, as well as in Lemmy's boss battle.

New Super Mario Bros. U / New Super Mario Bros. U Deluxe
Rubber balls return in New Super Mario Bros. U, but Lemmy only balances on one instead of casting them, instead throwing bouncing bombs at the player.

Super Mario Maker 2
In Super Mario Maker 2 versions 3.0.0 and later, Lemmy balances on top of a magical ball while shooting more out of his wand. They have the same behavior as in New Super Mario Bros. Wii.

Puzzle & Dragons: Super Mario Bros. Edition
In Puzzle & Dragons: Super Mario Bros. Edition, Lemmy is seen riding a rubber ball in his fights in World 2-Castle and World 2-Airship.

Mario & Luigi: Paper Jam
In Mario & Luigi: Paper Jam, Lemmy rides a giant rubber ball in one of his attacks in Neo Bowser Castle, when fighting alongside Morton Koopa Jr. and Iggy Koopa. Lemmy rides his ball to try to crush Mario and Luigi, but he fails if he is hit by the boomerang.

Paper Mario: Color Splash
In Paper Mario: Color Splash, Lemmy balances on a striped green-and-red ball, using it to roll around the Emerald Circus. During the boss battle, he ditches it by transforming his magic wand into a spiked yellow-and-black ball, referred to as a Wonder Ball. Mario must distract Lemmy by using the Disco Ball Thing Card and then use the Ice Pick Thing Card to pop the Wonder Ball, or Lemmy will use his Wonder Ballistic attack for a total of 163 damage.