Jason Beck, also known as Beck Gold, is a recurring antagonist introduced in the first episode of the series. He is a flamboyant criminal who first appears as the kidnapper of R. Dorothy Wayneright, which brings him into direct conflict with the professional negotiator Roger Smith. Beck is a man of distinctive appearance, almost always dressed in a signature golden yellow suit, complemented by a black dress shirt and a gold tie. He maintains meticulously styled blond hair, often grooming it with a comb he keeps in his breast pocket. This obsession with a gold color scheme extends to his personal belongings, his customized giant robots, and his preferred aesthetic.

By nature, Beck is a theatrical and eccentric individual who approaches even serious situations with a jovial, maniacal, and sarcastic demeanor. He often behaves like a jester, taking any interaction and giving it a comical slant while frequently complimenting his own attire and achievements. Despite his overtly buffoonish and narcissistic personality, he is a highly intelligent and skilled mechanical designer. Beck has demonstrated a tremendous mechanical inclination, possessing the ability to design, construct, and operate his own Megadeus units from scratch, which he typically names after himself, such as the Beck Victory Deluxe. His technical prowess is such that he was specifically sought out by the powerful Alex Rosewater to reconfigure the Megadeus known as Big Fau. He has also shown an affinity for creating sophisticated gadgetry, imitation humans, and even a precise working replica of Roger Smith's torso and head.

Becks primary motivation throughout the series is his obsessive desire to defeat and humiliate Roger Smith. After being publicly humiliated by Roger during the initial kidnapping case, Beck's schemes became a persistent effort to get revenge. He views Roger as his arch-nemesis, often calling him crow-boy in reference to his black attire, though Roger consistently dismisses him as merely a small-time crook. While his intentions are dubious, Beck frequently uses Dorothy as a key factor in his plans, whether by kidnapping her or attempting to use her android systems as a power circuit for his machines. He is also driven by a desire to erase the memories related to the Megadeus, as these recollections make him feel deeply unpleasant.

Becks role in the story evolves from a sinister and dangerous threat in his first appearance to a more comical, recurring nuisance. He is a very persistent man, but he does not learn well from his mistakes, often using similar traps and plans that always result in the same defeat. He is usually accompanied by two henchmen, and his schemes degrade in severity from grand larceny and sabotage to almost farcical attempts at revenge. Despite this, his technical skills keep him relevant. He becomes an agent for Alex Rosewater after being threatened with execution, though he is unhappy with this arrangement despite a successful attack on Roger. His dissatisfaction with helping the powerful CEO leads him to betray Rosewater. In a significant turn, Beck ends up aiding Roger in the final episode by instructing Dorothy on how to activate Big O's Final Stage, an act that aligns with his apparent desire to ridicule the larger machinations of the world.

Becks notable abilities lie almost entirely in his mechanical genius. He has the skill to hotwire and control androids, disable sophisticated security systems with crude tools, and build fully operational mechs. While his inventions are advanced, they often fail dramatically due to some inherent design flaw or his own overconfidence. His character experiences a subtle development from a purely greedy villain to someone who, despite his comical failings, becomes an unpredictable wild card in the larger conflict, ultimately choosing to defy a greater power for his own obscure reasons.