So there's this one ally of the heroes that's really annoying and everyone, fans and writers alike, hates. How can you get the heroes to take out your rage on them without making the heroes into jerks or making people feel sorry for them? Make the Scrappy into a villain! An in-universe variant of Ron the Death Eater. May be a symptom of Running the Asylum.
ExamplesFilm - Animated
- The Incredibles: Buddy was so obsessive and clingy with Mister Incredible that his idol had to use the Ejector Seat on him. After the Bomb Voyage fiasco, Buddy underwent a Face–Heel Turn to become the murderously vengeful villain Syndrome.
- The Trope Namer Scrappy Doo got this in the first Live Action Scooby-Doo movie. After being kicked out of Mystery Inc Scrappy took control of Monster Island and used the eponymous creatures to get his revenge on them.
- In Captain America: The Winter Soldier it turns out that jerkass Senator Sterns from Iron Man 2 is an agent of Hydra. He is arrested at the end of the movie.
- One season of Law & Order: SVU introduced an annoying lab tech who may well have been designed to invoke this trope when he snapped and started murdering people after being chewed out for a mistake.
- Michael Cole was, at times, so despised by the fans that the WWE turned him heel in late 2010 and had several major opportunities to see people like Jerry "the King" Lawler and John Cena beat the crap out of him, much to the audience's delight.
- The finale of Sam & Max: Beyond Space and Time revealed that the eminently annoying Soda Poppers had been behind the events of the last three games, accidentally responsible for the one before that, and had taken over hell, to boot.
- Moneybags in Spyro 2: Ripto's Rage! was a rich jerk on the hero's side who made you pay through the nose to make any progress. In Spyro: Year of the Dragon he joins the villains while still keeping the same role.
- Mass Effect 3: Human ambassador Udina began as an annoying political hindrance to Shepard trying to save the galaxy. By this game, he's involved in a Cerberus attempt at a hostile takeover of the Citadel and murder of the rest of the Council.
Hello, Unknown Troper. You'll need to get known to lend a hand here.