Mario was called Jumpman in the original 1981 arcade game Donkey Kong.
Nintendo released Donkey Kong in arcades in 1981 after Shigeru Miyamoto designed it with a team that included Gunpei Yokoi. The player-controlled carpenter must climb platforms and avoid obstacles while rescuing a damsel from the giant ape Donkey Kong.
Nintendo later renamed Jumpman Mario, reportedly in reference to Mario Segale, a landlord associated with Nintendo of America. The character’s occupation was also later changed from carpenter to plumber, matching the settings and stories of subsequent games.
Jumpman is therefore the original in-game label, not a separate hero who merely resembles Mario. Donkey Kong also introduced the modern versions of both Mario and Donkey Kong, although their roles and relationship changed considerably in later Nintendo titles.