The Ren & Stimpy Show (1991)

S2E15 Stimpy's Fan Club

Ren can't help but feel envious of the endless fan mail Stimpy receives. To cheer him up, Stimpy names Ren the president of his Fan Club. This newfound title sends Ren into a spiral of delusions of grandeur, leading him down a path of madness as he becomes increasingly consumed by his inflated sense of self-importance.