The common Hollywood Nerd is, at worst, a bit annoying. Sure, he might have No Social Skills and be overly fond of telling people about his Pokémon collection, but his heart is generally in the right place.
And then there's this guy (though definitely not always a guy). Either his lack of social niceties is caused by a complete disregard for other people, or else the loneliness and rejection they've led to has turned him bitter and twisted. Either way, he's out to get everything he's ever wanted, by any means necessary, including revenge on any real and imagined slight he's suffered.
He's often an Entitled Bastard who thinks that his superior intelligence (which may or may not actually exist) should automatically make him adored and successful, and that the people failing to give him his due deserve some sort of exaggerated punishment for it. He has often genuinely been bullied and hard done by, but by the time he gets to his Motive Rant he's always done so many horrible things that the protagonists will be less than sympathetic - no matter how many lockers you were stuffed into, it just doesn't justify sending demons to rip the Jerk Jocks' living souls out of their bodies.
The Nerdy Bully and Insufferable Genius are this trope's somewhat more benign cousins, who settle for being Jerkasses instead of going straight for the outright villainy note . On the flip side, the Evil Genius and Mad Scientist is what the Evil Nerd often wants to be but can't quite live up to - while he may or may not be smart, he's fundamentally too small and dull a person to conceive of a genuinely visionary plan, evil or otherwise.
Since the Evil Nerd is generally not the fittest or best-looking, there is likely to be overlap with Brains Evil, Brawn Good and Beauty Equals Goodness as he faces off against the better-groomed and more physically capable heroes. Compare the Evil Cripple, whose broken morality is also symbolised and/or caused by a more visible handicap, as well as Nerdy Bully, which he may overlap with or have graduated from if he's past his high school years.
Contrast Nerd in Evil's Helmet, where the villain's nerdiness offsets his evil instead of being the foundation of it.
- The Spirit of '76 has science geek and UFO buff Rodney Snodgrass, who wants to capture the time travelers and use them for his high school science fair project. He steals part of their time machine and destroys it by accident, almost causing them to be trapped in The '70s forever.
- Ghostbusters (2016) has Rowan North, a geeky guy whose misanthropy pushes him to summon evil ghosts. His Motive Rant toward the Ghostbusters leaves them unimpressed.
- The Technical Boy in American Gods is a version of this trope that's actually achieved the elevated stature he craves. Instead of being bitter and resentful, he's smug and conceited about how his intelligence has allowed him to be successful even in the complete absence of any social skills.
- Norman Birdwell in the first of the Blood Books is an odious loser who summons demons in a poorly considered effort to become cool and get girls, not caring that every time he sends the demon out to do a favour for him, it kills an innocent before returning. Even other nerds can't stand him, even aside from the demonology thing — he keeps getting into heated arguments with them about roleplaying games and just generally being a Jerkass.
- Harold Lauder in The Stand is fat, gross and considers himself the only fully sentient person around. He actually flirts with subverting this trope since his genuine intelligence makes him valuable in the post-apocalyptic world and he finally gets some of the social acceptance he's been lacking, but in the end he can't overcome his baggage and joins the Big Bad.
- Buffy the Vampire Slayer fought a few, most notably the Trio in Season 6. Notably, they were the least threatening of her seasonal Big Bads, with their blundering being used mostly as a backdrop for Buffy's own struggle against depression, and their petty sense of entitlement and failure to consider the ramifications of their actions contrasted against the Evil-with-a-capital-E that she usually fought.
- The Technical Boy in American Gods may be the literal embodiment of the trope, being the God of Technology and the Internet who takes the form of the most odious sort of tech-geek. Interestingly, he's even more evil than his book counterpart, reflecting the creators' belief that nerds have gotten more evil since the book was published.
- Robert Daly from the episode "USS Callister" of Black Mirror is a nerdy, asocial programmer. He disproportionately takes out his frustrations with his co-workers by creating virtual copies of their minds, placing them in a video game mod, and abusively forcing them to reenact his power fantasies. He finds it easier to use his technical skills to force clones of his coworkers to act out his sci-fi fantasies than to actually learn how to get along with them in real life.
- The Big Bad from Season 2 of Veronica Mars, Cassidy Casablancas, initially seems like a sweet, geeky foil to his douchy older brother Dick but turns out to be far more ruthless and psychotic than Dick ever was. Downplayed in that the bullying and abuse he's suffered for being small, brainy and self-conscious rather than confident and athletic like Dick isn't the direct motivation for his crimes, but it's implied that it is part of what made him cracked enough to be capable of them.
- Evil Abed from Community is every bit as dorky as the real Abed, but has gone from being bad at relating to people to outright hurting them For the Evulz and exploiting them for his own bizarre plans.
- One of the sample Heroes in Beast: The Primordial is a man who grew up being praised for his book-smarts but who has found that those don't amount to success and popularity in the real world. He's concluded that that must be the Beasts' fault, somehow, and so goes around hunting them while wearing an ill-fitting Badass Longcoat and a Fedora of Asskicking.
- The sample adventure for the Buffy the Vampire Slayer roleplaying game has as its main villain a teenager named Keith Dicks, who is unpopular, unaccomplished and spends most of his time watching crappy science-fiction and fantasy shows on TV. Through a wish granted by an evil genie, Keith has gained the power to make the protagonists of his favorite franchises come to life, and is sending them out to kill everyone who's been mean to him.
- City of Heroes villain Midnight Master is an evil alternate universe version of friendly loser Percy Winkley, in Praetoria he got fed up with being a laughingstock and decided to show them all... and it worked.
- The Simpsons: Comic Book Guy often gets this treatment in Treehouse of Horror episodes. For example, one episode casts him as The Collector, an evil supervillain who collects people like comic books and stores them forever in plastic bags. The prize of his collection is Lucy Lawless / Xena, who he kidnaps.
- Mandark from Dexter's Laboratory, since Ego Trip, became this. Earlier, he was once the bitter rival of the main character, Dexter. Since then he is now a full-on villain. In his "first meeting" with Dexter, the latter makes fun of him for his hippie attire and name, "Susan". This enrages Mandark and he becomes Dexter's Arch-Enemy.
- Control Freak is a recurring villain in both Teen Titans and especially Teen Titans Go!. He's a fat, pasty, gonk geek who's completely obsessed with pop culture. He frequently uses his Universal Remote Control to warp reality and make the Titans' lives miserable, usually by placing them inside television programming — including the Teen Titans Go! cartoon itself.