Challenge of the Superfriends (S04E01)

Bloo feels envious when Mac is selected to be the partner of an imaginary superhero companion. As Mac revels in his newfound role, Bloo’s jealousy escalates, prompting him to devise a plan to reclaim his position as Mac's favorite. Meanwhile, the imaginary adventures take unexpected turns, leading Bloo to confront his feelings and the value of friendship. Ultimately, he learns that supporting Mac's joy can be just as rewarding as being the star of the show.