Baron Silas Greenback is the arch nemesis of which cartoon hero?

The answer is Danger Mouse because Baron Silas Greenback serves as the primary antagonist throughout the animated series. Danger Mouse, a British secret agent and the world's greatest super-spy, battles against the forces of evil and Greenback is his most formidable adversary. Greenback, a villainous toad with an insatiable thirst for power, constantly hatches elaborate schemes to conquer the world, but is consistently foiled by Danger Mouse and his sidekick, Penfold. Their ongoing battles form the central conflict and dynamic between the two characters, making Baron Silas Greenback the arch-nemesis of Danger Mouse.