Disney’s Up is 100% pulp fiction. If this story had been written and published in Amazing Stories or Weird Tales, it could not have been any more pulp-y than it already is.
The main character takes an unusual mode of transportation and finds himself in a paradise. Here he comes across a friendly animal that leads him to the animal’s master. This master is a megalomaniacal explorer who appears to have slipped over the edge of sanity, using his mania as a means to ensure his solitude and terrorize the locals. After a brief struggle, the main character saves the friendly animal, thwarts the megalomaniacal explorer who falls to his death, and then the main character returns home via a similarly unusual mode of transportation with a new lease on life and a story few people would ever believe.
When you strip out the specifics, the names, and the fact this movie was made by Disney/Pixar, Up resembles countless stories from the pulps (and proto-pulps). There are echoes of Haggard and Kipling, Burroughs and Doyle all throughout the film, which is something I love, but which I feel too many people sail right past without acknowledging.
Pixar gets a lot of credit for originality, most of which is deserved, and I certainly don’t mean to imply a lack of originality in Up. The age of the hero, Carl, and his villain, Muntz, and the relatively subtle use of racial dynamics with Russell set this movie apart from many of the other movies of its time, even almost 10 years later. In fact, Up’s use of retirees for protagonist and antagonist still sets it apart from the bulk of film history. Such distinction becomes singular if you limit the criteria to Disney and Pixar films.
So while there is originality here and while this specific plot hasn’t been done in this fashion, Up follows a rich history of pulp fiction, particularly the subgenre of Lost World adventure stories, as the second paragraph makes pretty clear. Carl may be a septuagenarian, but he is a pulp hero—complex, multi-faceted, flawed but brave, determined to achieve his goal but wise enough to step back when realizing there’s more to life. Think back to Burroughs’ Caspak and Doyle’s The Lost World. Consider Flash Gordon and his exploration of the universe or Doc Savage as he fights back against people bent on conquering the world through the use of futuristic technology.
Muntz is the villain who once started out as an inspiring figure to people. His devotion to his cause at the cost of personal relationships, his rejection of social norms, his retreat to self when questioned over methods and results—all of these led him away from the hero status of his youth, a status he still believes he possesses as evidenced by his interactions with Carl. You can see echoes of Captain Nemo and Captain Ahab in the way Muntz’s obsession takes him down a dark path and in the way Carl starts down the same path until he sees where it ends. I could even go so far as to connect Muntz to Joseph Conrad’s Kurtz in Heart of Darkness (made even crazier by Marlon Brando in Francis Ford Coppola’s adaptation Apocalypse Now), but by then I’m heading deep into English professor territory. At the very least, Muntz is a character with motivations of his own and not simply evil for the sake of the story.
I loved Up. I think it’s safe to say most of the world loved it, so I’m definitely not alone. I’m sure I’m not the first to make the connection back to the pulp works of the late 19th and early 20th Centuries, but I haven’t yet read any deep analyses. The closest I’ve come across is Roger Ebert’s review where he throws out a momentary oblique comparison to The Mummy, Tomb Raider, and Indiana Jones, and that’s just to scenery and setting. If anyone knows of a detailed critique of the film including such references, I’d love to read it. Maybe I’ll just have to write it myself if there isn’t one.
 Originally I’d written Pellucidar, which is Burroughs’ Hollow Earth setting, itself an homage to Verne. Hollow Earth is definitely related to Lost World, but requires movement through the Earth’s crust instead of hidden locations on the Earth’s surface. Incidentally, Wakanda for Marvel and Gorilla City for DC are also Lost World settings, a detail that frequently is overlooked.
 Doyle even included balloons as a mode of transportation, a coincidence that is not lost on me.
 As I was getting ready to post this, I came across this thread on Reddit’s “Fan Theories” subreddit. I knew I couldn’t have been the first, and I’m glad to see I wasn’t. I wouldn’t say I agree with the theory, but I’m glad someone else appears to have made the connection. I have found other throw-away references that don’t go into any real depth, but that’s not what I’m looking for.