Boomerang

Boomerangs are a type of weapon that have made numerous appearances throughout the Mario franchise. When thrown, a boomerang will fly forward, harming any foes who happen to be in its path, then circle back to the user. They are the weapon of choice of the Boomerang Bros, but can also be used by Mario, Luigi, Princess Peach, Toad, Toadette and Rosalina upon grabbing a Boomerang Flower.

Super Mario Advance 4: Super Mario Bros. 3
A special blue boomerang makes an appearance in some of the World-e levels of Super Mario Advance 4: Super Mario Bros. 3. When thrown, this boomerang defeats most enemies it hits. It briefly flies forward before turning around, though it only does so once; as such, Mario must catch it (by holding ) if he hopes to re-use it. However, it disappears upon level completion, much like a Goomba's Shoe.

Certain Boomerang Bros are also shown using these boomerangs in Slidin' the Slopes, Bowser's Last Stand, and Bowser's Airship 2, and if they are defeated while one of their boomerangs is out, it drops for the player's use.

There is also an e-Reader card released only in Japan that uploads this boomerang to the player's inventory, allowing Mario to use it in any stage.

Paper Mario: Sticker Star
Boomerangs appear in Paper Mario: Sticker Star as stickers that are sometimes dropped by Boomerang Bros upon defeat. When using the sticker, Mario tosses a boomerang that strikes all enemies in its path.

The Boomerang can also be added to the Sticker Museum as #93, alongside other enemy-based stickers.

Super Smash Bros. series
Boomerangs appear as items in Super Smash Bros. for Nintendo 3DS, Super Smash Bros. for Wii U, and Super Smash Bros. Ultimate. The boomerang that appears in these games is said to be and designed after the one used by Boomerang Mario in Super Mario 3D Land. They function like standard boomerangs in that they are thrown to attack opponents and return to the thrower, though for every time the player catches it, the boomerang's attack becomes stronger.

Mario Kart 8 / Mario Kart 8 Deluxe
In Mario Kart 8 and Mario Kart 8 Deluxe, racers can get a boomerang to throw up to three times, via a Boomerang Flower. Opponents can steal one by pressing while near one, boosting into a boomerang holder with a Mushroom, or using a Boo (Deluxe version only), however.

A single blue boomerang with a red stripe appears on the logo for the sponsor Boomerang Bros. International Airlines, though the color changes in some of the logo's variations.

Mario Kart Tour
The Boomerang Flower returns in Mario Kart Tour as the special item of Baby Mario, Baby Luigi, Larry, Toad (Pit Crew), Boomerang Bro, Shy Guy (Ninja) and Yoshi (Kangaroo). The boomerang now orbits the user's kart twice before flying off. It can also collect coins and destroy track hazards. Boomerang Bro's boomerang appears in his trick animations.

Super Mario Party
Boomerangs also appear in Super Mario Party as the weapons the players use to take out the Pokeys in the minigame Home on the 'Rang.

Dr. Mario World
Boomerangs were added as items in the 1.3.0 update for Dr. Mario World. When used, they clear out a selected row hitting everything in it once. Unlike other objects that travel in a path, they are not obstructed by Empty Blocks. Of the in-stage items, this is the only one that is not available as a VS reward and much rarely as a prize in events, as the main means of obtaining them are either through the Boomerang Pack in the shop or as an offer for diamonds when the player frequently failed a stage in stage mode. If players do not have any more free uses of this item, a price of 12 diamonds is required to use it.

WarioWare: Get It Together!
Mona uses a boomerang to interact with Microgames. When is pressed, Mona's hover scooter stops and she throws the boomerang, which can be steered the same way with. Mona also uses her boomerang in her cutscene to threaten her pets after they mess up her bedroom. In promotional material, Wario vaguely calls the boomerang the "Stick Thingy".

Paper Mario: Sticker Star

 * Item description: "Sometimes dropped by Boomerang Bros. Provides a boomerang that hits all foes in its flight path."
 * Sticker Museum description: "A boomerang beloved by the Boomerang Bros. Put your elbow into it to get some force into your throw!"

Super Smash Bros. for Nintendo 3DS / Wii U trophy
Blue indicates exclusive to the Wii U version.