Rick Riker (Drake Bell) is an unpopular student at Empire High with his only friend Trey (Kevin Hart), living with his uncle Albert (Leslie Nielsen) and Aunt Lucielle (Marion Ross). His crush Jill Johnson (Sara Paxton), who hardly notices him, is dating Rick's bully Lance Landers (Ryan Hansen). Rick and Trey are then shown to be on a school trip to an animal research lab. In the lab Rick meets Lou Landers (Christopher McDonald) who coughs up blood because he is terminally ill. Dr. Strom, the head researcher at the lab, then shows his seven mutated dragonflies, though there are only six there because one has escaped which then bites Rick, and causes his neck to swell.
The scene then goes to Rick's house where his Aunt Lucille and Uncle Albert are talking on the couch when Rick comes in. He is very sick, and throws up in a fish tank because of his illness and goes up to his room. Albert and Lucille believe Rick is acting strange, so Albert proceeds to talk to Rick. Rick then passes out from the bite.
He wakes up the next morning, with a strange video sent to him from a man wanting to speak to him, later adding Rick as a friend on Facebook. Meanwhile, Lou Landers gets into a scientific accident, transforming into the Hourglass who feeds on human life. At a science fair, with a comically rude and mean-spirited Stephen Hawking who gets physically hurt throughout the film, Rick gets into mishaps, such as becoming stuck to water fountains. He then realizes he has superpowers such as the ability to walk on walls, has incredible strength, but cannot fly. He tests his strength in an alleyway, then decides to test how he can walk up walls. He climbs up and begins to break dance, then has a lie-down on the wall and a cat walks up the wall beside him. He then sees an old woman about to be hit by a truck in the road, and just as she is about to get hit he pushes her out of the way and the truck collides with him stopping it.
After his heroic feat he is congratulated by passers-by, but as they are congratulating him he looks to his right and sees he has accidentally pushed the woman into a woodchipper and the dog she was holding the lead of up is slowly getting pulled up into the machine as well. Trey offers to become his sidekick, but Rick resigns. His Uncle and he have a brief fight, which reminds Rick when he was younger and rich with his parents who die in a spoof of Batman Begins. His father urges him to invest of all his money in, not Google, but Enron.
Rick later watches the girl of his dreams, Jill, who leaves with Lance in his car. Rick wants a car, and he sets out to get money from the bank. He fails though, with no credit or payment.
After his uncle is quickly injured, Rick is met by Xavier (Tracy Morgan) at his school for mutants ala X-Men. Rick is told to make a costume, which he does (and later improves), and he becomes known as the Dragonfly. He quickly becomes a sensation, until his fight with the Hourglass, who ends up cutting him with little hourglass blades. The Hourglass then escapes.
Jill is then seen walking in an alleyway and is attacked by thugs, but the Dragonfly saves her. The two then try to kiss, but encounter difficulties as Dragonfly is hanging upside down. They eventually kiss for the first time, and Jill thanks him.
The scene then goes to a Thanksgiving dinner at Rick's house. During Thanksgiving Landers visits the family (everyone is unaware he is Hourglass). He nearly catches Rick dressed as the Dragonfly, but later manages to figure out his secret identity.
Just as Rick and Jill are about to fall in love, the Hourglass comes in and murders Aunt Lucille. After a comical funeral, Rick decides to throw in the towel as a superhero.
Trey and Uncle Albert find Rick after the funeral, and convince him to find and defeat the Hourglass. At a ceremony, Lou, with the help of a Microsoft "Death Machine Maker" disk, concocts a plan to make himself immortal by killing thousands of people. Rick finds out where he plans on doing this; a convention of all races, right next to a comic-con. Lou Landers is awarded the Douchebag Of The Year award, and encounters Rick who believes someone else is the Hourglass. He returns in costume and critically injures Jill. (If you look closely you'll see black suit spider-man.)
After a sincere speech given by Stephen Hawkings to Rick (which Rick points out are the lyrics to Celine Dion's Taking Chances), he dons the Dragonfly suit, and battles the Hourglass on the rooftop. Dragonfly heals Jill, but the Hourglass throws an Hourglass bomb onto Dragonfly's crotch. Dragonfly then puts his crotch next to Lou Landers' face, which blows up, killing him. He also saves Jill and himself from falling to their deaths by finally growing wings and being able to fly.
The film ends with the Dragonfly and Jill flying in the air sky high, with Rick giving his final narration, only to be stopped short, as both are hit by a helicopter.