Short answers, pulled from the story.
Birdie first appeared in the original Street Fighter game on the 25th of May 1987 as a non-playable opponent. He remained a background figure fighting Ryu or Ken Masters before disappearing from the series entirely for over a decade.
Capcom stated that his paler complexion in the original game was due to an illness, which served as the official explanation for the visual shift. Artist Naoto Kuroshima, known by his nickname Bengus, handled the redesign and jokingly noted in concept art that the character had been kidnapped by aliens.
Birdie remained unused in any Street Fighter games until his inclusion in Street Fighter V, which was released in 2016. This marked his first playable appearance in over two decades and was driven by game director Takayuki Nakayama.
Artist Naoto Kuroshima, known by his nickname Bengus, handled the redesign and decided to make him black as development progressed. The contrast between his original white sprite and his new dark skin was so stark that Bengus suggested in concept notes that the character had been kidnapped by aliens.
Birdie freeloads in Karin Kanzuki's house and becomes one of her allies to fight Shadaloo. His role emphasizes his function as a comedic relief character inspired by his previously displayed large appetite and low work ethic.
Wired writer De'Angelo Epps called Birdie the epitome of a Black caricature, while ComicsAlliance writers Chris Sims and David Uzumeri questioned if his inclusion perpetuated harmful stereotypes. Kyle A. Harris noted that Birdie fit a similar racial template to fellow Street Fighter characters Balrog and Dee Jay as hulking figures with brash personalities.