Short answers, pulled from the story.
Oro was developed by Yūji Imamura who served as graphics designer and Tomoshi Sadamoto who acted as producer. The initial concept drew inspiration from the Gracie family and their Brazilian Jiu Jitsu lineage before evolving into an ancient martial arts master.
Oro first appeared in Street Fighter III: New Generation during the game's development phase. He later returned as a playable character in Street Fighter V fifth season after appearing in various story modes including Dhalsim's and Karin's narratives.
Oro stands 161 cm tall with yellow skin solid red eyes and a bald head featuring few strands of long hair. He fights using only one arm while carrying a tortoise named Yamasen in the other hand and wears a dark red sash around his body.
The development team chose to have Oro hold a turtle with his restrained arm because they felt it preserved the original 2D sprite art representation better than previous ideas. This decision maintained his role as a hermit while adding visual interest to his fighting animations.
Reviewers gave mixed reception noting that his design did not fit the series aesthetic or appeal to Japanese audiences due to exposed genitals and odd playstyle. Some critics compared him to Yoda from Star Wars while others found his alien appearance creepy yet appreciated his self-handicapping approach.