Short answers, pulled from the story.
Birdie is a fighter representing the United Kingdom who first appeared as a non-playable opponent in the original Street Fighter in 1987. He became playable in Street Fighter Alpha and appeared in Street Fighter Alpha 2 and Alpha 3 before returning in Street Fighter V. His appearance changed substantially between game eras, and he has been a subject of ongoing debate about racial representation in fighting games.
Birdie was depicted with pale skin in the original 1987 Street Fighter and as Black in Street Fighter Alpha. Capcom's official explanation is that illness made him pale in the first game. Designer Naoto "Bengus" Kuroshima, who handled the Alpha redesign, offered a different account in his concept art notes, writing that Birdie had been "kidnapped by aliens."
Artist Naoto "Bengus" Kuroshima redesigned Birdie for Street Fighter Alpha. Bengus consulted colleagues on how to approach the new look and worked through what would and would not succeed in the redesign.
Street Fighter V director Takayuki Nakayama wanted a comedic character for the game and selected Birdie to fill that role. He drew on Birdie's established traits of a large appetite and low work ethic. Series producer Yoshinori Ono helped shape the final design, which gave Birdie a pronounced gut and a moveset tied directly to eating.
Birdie has been widely criticized as a racial caricature. Wired writer De'Angelo Epps called him "the epitome of a Black caricature," and ComicsAlliance's Chris Sims described him as "quite possibly the most racist video game character ever." Academic analysis published in the journal Technological Forecasting and Social Change also identified him as an egregious example of negative portrayal in fighting games.
Birdie's idle animation in Street Fighter V shows him flicking snot. It is one of only a small number of idle animations in the game capable of dealing damage to an opponent.