Quentin Beck was a former special/visual effects designer hired by Oscorp Industries to work on the visual graphics for their computer-animated commercials. Despite the amount of money he was getting paid for his computer work, Quentin still wanted more physical recognition for his work and tried to become an actor but failed due to his horrid acting skills. Nonetheless, he wouldn't get his chance to shine until he was approached by agents of the Master Planner, a mysterious crime lord operating in New York, to utilize his visual FX talents for crime as part of the Master plan. Accepting the offer out of a sense of pride, Beck built for himself a armored suit equipped with holographic projectors and other numerous mechanical devices, and adopted the persona of a mystical sorcerer by the name of Mysterio.
Beck has since gone on to be recruited into the Sinister Six initiative at Oscorp Industries to counteract S.H.I.E.L.D.'s Avenger Initiative.