Birdo

Birdo (, Catherine) is a character from the series.

Origin
Birdo made her debut in the Japan-only game  (repurposed as Super Mario Bros. 2 for international markets) as a recurring boss. She is a pink dinosaur creature with a nozzle-like mouth and a red bow. In her later appearances, she wears a diamond ring. As a boss character, Birdo attacks by spitting eggs at the player. She can be defeated by grabbing the flying eggs and throwing them back at her three times. Later worlds introduce different colored varieties of Birdos which attack by spitting fireballs at the player.

Like much of the content in Doki Doki Panic, Birdo was retained when the game was reworked for its North American release as Super Mario Bros. 2. Since then, Birdo has appeared in numerous Mario series games, being a boss once again in ' and ', and a playable character in many installments of Mario spinoff series such as ' and '.

Birdo's gender is described as "indeterminate" in Brawl, referencing a long-standing debate in her home series. She was initially described as a male who "thinks he is a girl" in Super Mario Bros. 2's instruction booklet, suggesting that she is transgender. Most other game appearances refer to Birdo as female, but usually ignore her transgender identity as a whole. One mission in the 2008 Wii game  is based on the gender debate, tasking the player with finding evidence that Birdo is female after she was arrested for using the women's restroom.

As a stage hazard
Birdo appears as a stage hazard in the Mushroom Kingdom II stage. She appears on either side of the screen and shoots one or three eggs from her mouth before exiting to the side where it came from. Birdo can be attacked and will temporarily retreat after receiving enough damage.

Birdo's eggs deal damage to those they hit. These eggs can be shielded against, jumped on, knocked away with attacks, and air grabbed. When air grabbed they are usable as items that deal 24% damage when thrown normally, explode and deal 49% when smash thrown, and occasionally drop items after breaking. It is the only item in the series that can explode by input rather than chance.

Trophy
Obtaining the Birdo trophy unlocks the Mushroom Kingdom II stage.

Trophy
The Birdo trophy can be obtained as a challenge reward by clearing All-Star Mode on Hard difficulty.

As a stage hazard
Birdo returns as a stage hazard in the returning Mushroom Kingdom II stage.

Spirit
Birdo also appears as an Ace-class primary spirit. She can be summoned using the cores of and.