She first appeared as an antagonist in the beat-'em-up Final Fight from 1989.
Poison first appeared in Final Fight alongside Roxy. However, both women were replaced by the male characters "Sid" and "Billy" for the western SNES home console versions of Final Fight released in 1991. Allegedly, this was done to appease concerns of players beating up female characters.
Rumours about her gender, coupled with her very sexualized and curvy design, gained Poison unusual fame. She also had cameos in several Street Fighter games and the VS. series, was part of the cancelled Capcom Fighting Allstars, and made her playable Street Fighter debut in Street Fighter X Tekken.
Gender
Official pre-production concept art with "newhalf" text (1988)
Poison's gender has been the subject of much controversy and debate, and has been represented in conflicting ways over the years.
According to Final Fight game director Akira Nishitani, Poison was originally designed as a newhalf because of concerns that portraying violence against women would be controversial.
In 2014, Nishitani commented on twitter that in his personal view, Poison was a woman, but the character's canonical gender is left open to interpretation.
In 2012, Akira Yasuda, Poison's creator, has commented that he considers her to be transgender in American localizations, but cis in Japan.
In 2008 Yoshinori Ono, the producer of Street Fighter IV, stated that in Poison is considered a post-op transexual woman in American localizations, but in Japan she simply tucks her business away to look female. In a 2011 interview, he stated that Capcom does not have an official stance on Poison's gender, and it is left to the viewer's interpretation.
