<Li> Ed Asner as Carl Fredricksen (Jeremy Leary voiced Carl as a young boy). Docter and Rivera noted Asner's television alter ego, Lou Grant, had been helpful in writing for Carl because it guided them in balancing likable and unlikable aspects of the curmudgeonly character . When they met Asner and presented him with a model of his character, he joked, "I don't look anything like that ." (The appearance of Carl is meant to resemble Spencer Tracy as he appeared in his final film, Guess Who's Coming to Dinner .) They tailored his dialogue for him, with short sentences and more consonants, which "cemented the notion that Carl, post-Ellie, is a disgruntled bear that's been poked awake during hibernation". In Colombia, unexpected publicity for the film was generated due to the uncanny similarity of Carl with Colombian ex-president Julio César Turbay Ayala . </Li> <Li> Christopher Plummer as Charles F. Muntz . The name of his airship, the Spirit of Adventure, may have been inspired by Charles Lindbergh's airplane, Spirit of St. Louis . In various interviews, Pete Docter has mentioned Howard Hughes and real - life adventurers Charles Lindbergh and Percy Fawcett as inspirations for Muntz . </Li> <Li> Jordan Nagai as Russell . Throughout most of the film, he makes several comments to Carl that suggest that Russell's father and mother are no longer together . Russell's design was based on Pixar animator Peter Sohn . Docter auditioned 400 boys in a nationwide casting call for the part . Nagai, who is Japanese American, showed up to an audition with his brother, who was actually the one auditioning . Docter realized Nagai behaved and spoke non-stop like Russell and chose him for the part . Nagai was eight years old when cast . Docter encouraged Nagai to act physically as well as vocally when recording the role, lifting him upside down and tickling him for the scene where Russell encounters Kevin . Asian Americans have positively noted Pixar's first casting of an Asian lead character, in contrast to the common practice of casting non-Asians in Asian parts . </Li> <Li> Bob Peterson as Dug, the Golden Retriever misfit of Muntz's pack of dogs that can all communicate with humans through a device on each of their collars . Peterson knew he would voice Dug when he wrote his line "I have just met you, and I love you," which was based on what a child told him when he was a camp counselor in the 1980s . The DVD release of the film features a short called Dug's Special Mission, which follows Dug just before his first meeting with Carl and Russell . Dug previously appeared in Ratatouille as a shadow on a wall that barks at Remy . <Ul> <Li> Peterson also voiced Alpha, the Doberman Pinscher leader . Pete Docter has stated that Alpha "thinks of himself as Clint Eastwood". Despite his menacing appearance, a frequent malfunction in Alpha's translating collar causes his voice to sound comically high - pitched and squeaky, as if he had been breathing helium . The normal voice for his translator is a resonant, intimidating bass . With both voices, Alpha has a roundabout speech pattern that causes his sentences to be longer than necessary . </Li> </Ul> </Li>

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