The Super Mario Bros. Super Show! episode The Fire of Hercufleas
September 26, 1989
The fourteenth episode of the Mario animated series (seventeenth also counting the Zelda episodes), is about King Koopa stealing a jar containing the "Great Balls of Fire" from the retired hero Hecufleas, obviously based on Hercules. These are powerful fireballs that Hercufleas was assigned to guard, so Mario, Luigi, Princess Toadstool and Toad help him get back in shape and eventually fight Koopa to get back the jar.
The section of the episode where Hercufleas is trained by the four main characters is a spoof of the training montage from Rocky and its sequels, even featuring a music based on the Rocky theme, and ending with the hero climbing the steps to his temple and celembrating at the end.
DiC, that created the Mario TV show, holds no right over Metro-Goldwyn-Mayer's Rocky, in fact they only featured a minor reference to the movie.