Birdo

Birdo, known in Japanese as Catherine (キャサリン, Kyasarin, [kʲa.sa.ɾiɴ]), is a character in the Mario franchise. Her first appearance was as an enemy in Yume Kōjō: Doki Doki Panic, which was localized for English-language audiences as Super Mario Bros. 2. Since then, Birdo has been a recurring character in various franchise spin-offs. Initially, she was depicted as an antagonist, but has since been depicted as an ally. Birdo has also made several cameos, particularly in the Mario Kart series and the Japan-only Wii video game Captain Rainbow.

The English manual for Super Mario Bros. 2 describes Birdo as a man who "thinks he is a girl" and would prefer to be called Birdetta. This led to Birdo being interpreted as transgender, which would make her the first transgender video game character. Later releases of Super Mario Bros. 2 removed all mentions of her favored nickname. Starting with Mario Tennis, Nintendo has generally avoided her transgender roots; however, some games, such as Captain Rainbow and the Super Smash Bros. series deal with her gender. Birdo is also depicted as being romantically involved with Yoshi. She has received mostly positive reception in the Mario series, although her appearance and perceived gender identity have received mixed reception. She has made several appearances in other media, including the Super Mario Bros. Super Show!, as well as promotional material such as figurines and plush toys.