Original air date: 11/4/1995
I Was a Teenage Stimpy: Ren and Stimpy deal with the onset of Stimpy's puberty.
Who's Stupid Now?: To keep their show on the air, Ren and Stimpy have to switch their roles - Ren becomes the fat idiot and Stimpy the skinny jerk.
"I Was a Teenage Stimpy" contains examples of:
- Bratty Teenage Daughter: Stimpy becomes a parody of this trope, from hogging the phone to putting up a sign up that's obviously a play on "No Boys Allowed" in his room.
- Happier Home Movie: Ren watches old home movies of him playing baseball with a younger Stimpy.
- Leaning on the Fourth Wall: When Ren goes to smack Stimpy with an oar, he remarks "I should have done this back in scene 36."
- Painful Transformation: Stimpy as he goes through puberty.
- Parental Substitute: Ren is this for Stimpy, at least in this episode.
- Riding into the Sunset: Stimpy, upon becoming an adult, flies off into the sun at the end. Literally.
- Shout-Out: Stimpy's high school friends are overgrown versions of Archie and Jughead.
- Soap Punishment: Ren sticks the whole bar into Stimpy's mouth for talking back to him.
- Teens Are Monsters: Stimpy takes this to an almost literal degree with his metamorphosis and his rare grasp of the Jerkass Ball.
- You Are Grounded!: Ren says this to Stimpy for hanging out with delinquents. Coupled with "Forever".
"Who's Stupid Now?" contains examples of:
- Bowdlerization: The Reservoir Dogs reference during the milkshake scene has been removed from the dvd version. In addition, Ren’s prologue has also been removed.
- Cats Are Mean: Stimpy as he switches roles with Ren.
- Dogs Are Dumb: Ren as he switches roles with Stimpy.
- Dramatic Thunder: When Ren realizes he is now the "fat loveable idiot" and gives a triumphant maniacal laugh, lightning and thunder go off in the background.
- Executive Meddling: An in-universe example. The show's ratings are low, so the execs change Ren and Stimpy's roles, with Stimpy being the skinny jerk and Ren as the fat idiot.
- Humiliation Conga: As if his dream of being the "fat loveable idiot" turning into a nightmare isn't the worst of his troubles, Ren (who is now the fat idiot) gets ragged on by his boss and Stimpy (who is now the skinny jerk).
- No, You: At the beginning of the episode, the title duo are called in the director, who tearfully proclaims that he will hate to leave them. Ren smugly assumes that the director was fired, only for the director to quickly retort that it's him (and Stimpy by extension) who are getting canned.
- Personality Swap: When Ren and Stimpy switch places, Ren's intelligence decreases while Stimpy becomes meaner.
- Physical Attribute Swap: A side effect of the Personality Swap is that they trade physiques as well. So the Lean and Mean Ren and the Fat Idiot Stimpy become Fat Idiot Ren and Lean and Mean Stimpy.