Dexter's Laboratory: Ego Trip is an Annie Award-winning one-hour animated television special spawned from the Cartoon Network animated television series Dexter's Laboratory, produced by Hanna-Barbera (now Cartoon Network Studios) for Cartoon Network, that originally aired on December 10, 1999. It was later released on VHS and VCD in region 1 on November 7, 2000 while region 2's VHS release was July 23, 2001.
The film features the protagonist Dexter going to the future to see his futuristic versions of himself and his eternal rival Mandark to stop the latter from taking over the world.
Ego Trip was originally intended to serve as the series finale for Dexter's Laboratory, but due to a mixed reception from critics and high viewer ratings, the series was picked up for two more seasons starting with the first episode, Streaky Clean, airing on November 16, 2001.
Robots from the future come to destroy Dexter because he saved the future. Dexter defeats them and because of hearing that he saved the future, he travels into the future to find out what it is that he did.
After chasing his rival Mandark out of his lab when he tries to steal his latest invention, Dexter asks his sister Dee Dee to leave the lab, where she unintentionally enters a time machine stored near the entrance. Suddenly, Dexter is confronted with a group of red robots that have appeared from this time machine. They declare that they are here to "destroy the one who saved the future" and appear to make ready to attack Dexter. Dexter easily destroys them with the use of various tools and gadgets from his lab, as the robots mysteriously don't attack at all. Believing that he is "The One Who Saved the Future" that the robots spoke of, Dexter decides to travel through time to discover how "cool" he becomes.
However, in the first time period he visits, Dexter finds a tall, skinny, weak version of himself (known only as "Number Twelve") working in an office designing cubicles – and Mandark is his rich, successful – and sadistically abusive – boss. The kid Dexter berates his older self for allowing Mandark to bully him around and manages to convince him to come along to see how cool they become, but unwittingly leaves the Neurotomic Protocore and its related blueprints out in his cubicle, which Mandark steals as the two Dexters move forward in time.
In the second time period, the two Dexters meet their much older self, a wizened senior citizen Dexter about the same height as the kid Dexter (and Mandark's brain in a vat who cannot do anything other than complain about his situation). All the technology from the blueprints has been implemented, creating a utopian society of science and knowledge where anything can be materialized through the power of the Core. Due to his advanced age, however, Old Man Dexter can't remember anything about how he saved the world, so they travel back in time to find out.
In this final time period, which takes place between the first and second time periods, they find a dystopic world where everyone is stupid and fire and technology are forbidden, controlled by Overlord Mandark thanks to the Neurotomic Protocore. They meet Action Hero Dexter, who is tall, muscular and bald, fighting Mandark's evil robots. Action Hero Dexter explains that he and Mandark had been employed as corporate research scientists many years ago, where a jealous Mandark, unable to come up with the ideas Dexter could, stole them and passed them off as his own, using them to rise through the ranks and eventually take over the company in a coup – turning Dexter into the weak, cowardly, cubicle-designing Twelve.
Eventually, Mandark got a hold of the Neurotomic Protocore (due to Twelve's mistake in leaving it out in his cubicle) and attempted to harness its power, but set the core's positive flow to negative due to his incompetence with it, twisting his already evil mind. As the Core's now negative energies slowly swept over the world, they gradually numbed the minds of the population and allowed him to take over the world, hoarding all science and knowledge for himself. Dexter, no longer able to stand being enslaved and determined to stop Mandark, spent years digging underground to escape Mandark's tower, growing into his Action Hero persona in the process. By the time he emerged, the world was in its current state.
The four Dexters, determined to end Mandark's oppressive rule once and for all, go back to their ruined laboratory and use its resources to build a giant robot to invade his fortress. They manage to fight their way in (though the robot is destroyed in the process) and confront Overlord Mandark, now morbidly obese with brain matter, with his only form of locomotion being carried around his lair by a hook-and-winch. Outnumbered, Mandark evens the playing field by summoning his three selves from the other time periods to help him defeat the Dexters. A battle royal ensues, with each Dexter fighting the Mandark of their respective time period. Twelve eventually stands up to his Mandark, who he defeats before rallying the other Dexters to reach the Core's controls and save the world.
The fight ends in a stalemate, both groups restraining each other from pressing the Core's main button; however, Dee Dee emerges from the time machine welded into the Dexter’s now-destroyed robot. Her sudden presence confuses the Dexters and distracts the Mandarks, no one able to stop her as she – driven by her habit of seeing what buttons do – presses it herself.
With the positive flow of the Neurotomic Protocore restored, the world's intelligence returns to normal and causes Mandark's three time-displaced selves to be sent back to their own time periods, his head to burst open with only his brain intact, and his fortress to collapse. The Dexters, realizing in anger that Dee Dee was "the one who saved the future", create a group of five robots from the rubble to get revenge on her. The kid Dexter commands them to "destroy the one who saved the future" before sending them back to the past – unwittingly setting the whole series of events in motion himself.
The Dexters return to their original time periods. The kid Dexter returns shortly before he originally left, and sees himself fighting the robots he just built with his other selves. Realizing the time loop he has created (or rather that he has come back too far back to before he ever left), Dexter becomes confused when he attempts to wrap his head around it all but ultimately decides to ignore it and goes to eat a sandwich. When Dee Dee – who had already used the time machine to return home after saving the future – shows up, Dexter gathers up his food and walks away, still angry. Unaware of what she did, Dee Dee is left confused.
- The Time Machine is the same--if not similar--to the one used in DeeDeemensional.
- The first time traveling into the future, Dexter realized his original house interior was changed and his family moved out. This could explain--through cartoon logic-- the re-designing of Dexter's house in the new seasons.
- For her performance as Dexter in Ego Trip, Christine Cavanaugh won an Annie Award for Outstanding Individual Achievement for Voice Acting by a Female Performer in an Animated Television Production.
- The movie began production in April 1998 and was completed in November 1999. 
- This episode is also the last time Cavanaugh voices Dexter, before her retirement and death in 2001 and 2014 respectively.
- This episode was supposed to be the series finale of Dexter's Laboratory, as Genndy Tartakovsky left after producing the film (although he made two more episodes; one which aired during the theatrical release of the Powerpuff Girls Movie, "Chicken Scratch", and another one for the final produced episode "2Geniuses 2Gether 4Ever"). Due to the show's huge popularity, however, Cartoon Network wanted to give Dexter's Laboratory two more seasons. Genndy Tartakovsky has worked with Chris Savino on the first two seasons of Dexter's Laboratory, so Tartakovsky decided to hand his direction over to Chris Savino (storyboarder for season 1 and 2) during the revival the series, which premiered in 2001, and was met with mixed reviews.
- Dexter's Laboratory wasn't the last Cartoon Network show Chris Savino would run during its last two seasons, he also ran last two seasons of the Powerpuff Girls.
- Chris Savino is also recognizable for creating The Loud House for Nickelodeon, until he was fired for sexual harassment in 2017.
- Much of the show's new crew included Chris Reccardi (Director and writer of Ren & Stimpy and co-creator of the rejected Nickelodeon pilot The Modifyers) and Aaron Springer (writer and storyboard artist for the long-running Nickelodeon show, Spongebob Squarepants and creator of the rejected pilot Korgoth of Barbaria). Some of the show's old crew did stay for the revival run, such as Cindy and Clayton Morrow (who both also worked on the Powerpuff Girls and Chowder) and John McIntyre.
- This is the only episode that has cel animation with the season 3-4 design of Dad and the seasons 3-4 art style of Mandark's Laboratory. "Rude Removal" was the only episode after this to use cel animation, but neither Dad nor Mandark's Laboratory were seen in this episode, so it's hard to tell if they still had the newer designs. Most likely, they didn't, since the episode was produced in 1998.
- The character redesigns for seasons 3 and 4 were actually done by Chris Battle, who also designed characters for The Powerpuff Girls, AAAHH!!! Real Monsters, The Mighty B!, The Grim Advetures of Billy and Mandy, Dan VS, Teen Titans GO!, and The Ultra Violets.
- This is the final Dexter's Laboratory-related project to be produced by Hanna-Barbera before its closure in March of 2001 following the death of co-founder William Hanna, and the last to use traditional cel animation.
- Additionally, this special uses a CGI variant of the 1970s Hanna-Barbera swirling star logo (as seen after the end credits of fellow Cartoon Network series, The Powerpuff Girls) rather than the oval logo with Dexter's face, as seen throughout Season 2, or even the two rare 1996 prototype variants of the Cartoon Network Studios logos as seen throughout Season 1.
- This is the only episode rated TV-Y7-FV.
- For unknown reasons, Mandark dons on a more sinister persona and attire in contrast to his more nerdy look from the series and his lab is completely remodeled for unknown reasons as well. The reason for Mandark's sudden eviler turn and his lab's complete redesign is never explained, although it is likely that he became corrupted with power due to the potential of the protocore or that he simply became corrupted due to his past with Dark Forces.
- The movie has so far only existed in VHS and (an ultra rare) Video-CD formats. No release dates for future DVD or Blu-Ray has been announced.
- This is the last part of the series to be directed by Craig McCracken and Genndy Tartokovsky and the last part of the series in the 20th century.
- When Dexter kicked Mandark out of his house, the driveway is missing.
- Dexter was underdressed piloting his Dexo-Transformer, after summoning the Robo-Dexo 2000 to crush the last robot-- he's seen in his lab coat exiting it.
- When Dexter is escaping the Police in the first future, the front door closet is briefly shown to be open already. In the next scene, it is closed again.
- When a nude Number 12 was automatically dressed clothing by the machine, he was given a pair of black pants and a white coat, but with no signs of underwear visible underneath his pants. But when Number 12 is stripped off his clothes to be publicly spanked by Executive Mandark, he is seen in his underwear.
- When Dexter tells his wimpy self to stop typing, Wimpy Dexter's pants turn white.