The Real Ghostbusters (1986)

S05E10 Venk-Man!

When Peter is accidentally struck by Egon's experimental proton ray, he transforms into a muscular superhero, gaining impressive strength and a chiseled physique. However, this newfound power comes with a catch—it won’t last indefinitely. As Peter revels in his temporary abilities, he must navigate the challenges that arise from his brief stint as a superhero while grappling with the impending return to his normal self.