- "Adventure is out there!"
- —Muntz's famous catchphrase
Charles F. Muntz is the main antagonist of Up.
UpMuntz is a famous explorer and adventurer in the '30s that Carl and Ellie admired when they were kids. He flew around the world in his flagship airship, The Spirit of Adventure, collecting many rare specimens that are now preserved in the most prestigious museums. He is an avid dog lover and inventor, being able to train them to do practically anything, and has invented devices that translate their thoughts into speech. He is the master of many dogs, including Dug (who is now Carl and Russell's pet), Alpha, Beta, and Gamma.
Muntz is first seen in a newsreel titled Spotlight on Adventure, when an 9-year old Carl is visiting the movie theater. It is explained that he has recently returned from a lost land called Paradise Falls, having completed a year-long survey. Muntz is shown presenting his new-found treasure: a skeleton of a 13-foot tall tropical bird, whom he calls "The Monster of Paradise Falls."
However, scientists claimed the specimen to be a fake, and as a result, Muntz was removed from the National Explorers Society. Dishonored, Muntz declared in front of an oversized crowd that he will go back to Paradise Falls to get the bird, vowing that he would not return without a living specimen to prove himself right. Nothing was ever heard from Muntz following his departure, and soon he was all but forgotten.
Unfortunately, the countless years that Muntz spent at Paradise Falls corrupted him, his obsession driving him into insanity. Muntz became ruthless and paranoid, determined to do anything to obtain the bird and believing that anyone who came to Paradise Falls was after the bird to steal his glory, presumbly leading him to kill anyone he met.
When Muntz comes across Carl and Russell, he is touched by Carl's admiration and invites them to visit his aircraft, but it doesn't take long before his true nature reveals itself, when he learns that his guests have befriended the bird. He thinks they want to steal it, and is ready to kill them to retrieve it.
A chase begins, and Muntz succeeds at last in capturing the bird. Russell and Carl attack The Spirit of Adventure, and a battle ensues. In a final fight, Muntz breaks into Carl's house with a shotgun. Carl lures Kevin out of the house with a chocolate bar and knocks the shotgun out of Muntz's hands in the process. In a last resort measure, Muntz leaps out of the window after them and tries to grab Kevin's tail feathers. But Muntz's foot gets tangled in some balloon lines which detach from Carl's house, leaving him to fall thousands of feet below to his death.
Dug's Special Mission
Muntz is mentioned by Alpha in the short as "Master".
At the peak of his career, Muntz was a charismatic, smart and daring young man whose spirit inspired countless fans to look for adventure.
However, Muntz's quest for the bird that caused his disgrace destroyed him, as his search turned to obsession. Now a ghost of his former self, he became a heartless man, consumed by bitterness, paranoid to the extreme, and convinced that anyone who comes across him is after the bird. It is implied he killed two explorers already, and was intending to do the same with Russell and Carl. It is shown that Muntz's obsession is such that he doesn't care anymore for the rest of his collection, showing no hesitation to destroy some of his unique specimens when trying to take down Carl.
Muntz largely serves as parallel to Carl. He was a man broken because he lived obsessed with his former existence and desperately trying to relive it at any cost, showing what Carl could have become, had he not learned to accept loss and move on with his life.
- Muntz: "You know, Carl, these people who come here, they all tell pretty good stories. A surveyor making a map... a botanist cataloging plants... an old man taking his house to Paradise Falls... and that's the best one yet. I can't wait to hear how it ends."
- —Muntz to Carl on his victims
- Muntz: "Enough! I'm taking that bird back with me...alive...or dead!"
- —Muntz, his last words as he fights Carl, destroying his prized possessions with a sword
- Considering that Muntz is 23 and Carl 9 at the beginning of the movie, and that Carl is 78 by the time he takes off with his house, Muntz would be 92 years old when they meet.
- Muntz's full middle name is unknown.
- His name comes from Charles Mintz, who tried to sue Walt Disney for their Oswald the Lucky Rabbit character (from where the Mickey Mouse character later spawned).
- The name "Carl" is also a Germanic form of the name "Charles", suggesting that both characters are foils of each other and how Muntz represents a side of Carl.
- Muntz's objectives, actions and fate are arguably very similar or nearly identical to those of McLeach, the antagonist in The Rescuers Down Under.
- At the start of the film, Muntz was thought to have been a minor character, but is revealed to actually be the antagonist.
- When talking to Carl, Muntz talks about being on safari with Roosevelt. It is hard to tell if he means Theodore Roosevelt (a well-known explorer and adventurer) or one of Roosevelt's sons or his nephew, Franklin Delano Roosevelt, as Theodore Roosevelt passed away in 1919, when Charles was only 3 years old.
- The ultimate fate of Muntz was a work in progress for Pixar as they tried several versions to get him out of the way so the film could get back to Carl and his connection to Ellie. First they tried giving Muntz a chance to redeem himself to the point where it resorted to just him talking with Carl. Then they tried an ending that was reminiscent of Stanley Kubrick's version of The Shining where Muntz goes after Kevin in the labyrinth, where he's left to wander forever, but it felt more like Muntz's ending than Carl's ending. At that point, Pixar decided to place the climax on the Spirit of Adventure and one version had Muntz trapped in the house as it floats away, but it felt wrong due to the house being seen as Ellie. Another version had Muntz caught in a bunch a balloons and floating upwards, but it left an uncertainty as to whether he was dead. It was at this point that Pixar decided the best comeuppance for Muntz was for him to get caught in the balloons and fall with them. This is discussed on the DVD extra "The Many Endings of Muntz."
- Director Pete Docter indirectly mentioned in the DVD bonus "The Many Endings of Muntz" that Charles F. Muntz represented Carl's side that gave up on sanity after losing his most prized possession (Ellie to Carl, the bird to Muntz). In order for Carl to overcome his grief, his dark side had to be defeated, in other words, Muntz had to die. This commentary indirectly implies that Muntz did not survive the fall.
- Although he dies at the end of the film, he is shown to be still alive in the Kinect Rush: A Disney/Pixar Adventure video game, along with that his dogs are still evil in the game. It could be that he might have survived the fall, and that he used some different dogs.
- An Easter egg found in the Blu-ray version titled "The Egg" discusses an idea about Kevin's eggs restoring youth when consumed. The egg is what Muntz goes after in this version and it is not known if he still wants to clear his name. The idea was later abandoned.
- Christopher Plummer, Muntz's voice actor, played Captain von Trapp from The Sound of Music and voiced the Grand Duke of Owls from Rock-a-Doodle and voiced the narrator in the Madeline franchise.
- Muntz has his own musical theme composed by Michael Giacchino that's the first piece of music heard in Up. It echoes through the film when Carl and Russell meet him 70 years after young Carl sees Muntz in the newsreel at the beginning. A twisted version plays when Carl realizes Muntz's intention of capturing Kevin and killing anyone who gets in his way. Finally, the theme plays against Ellie's theme during the climactic battle between Carl and Muntz.