The special was released on DVD on March 29, 2011, and first aired on television on October 1, 2011, on Teletoon in Canada. The special premiered in the United States on Thanksgiving Day, November 24, 2011, at 8:30PM ET/PT on Fox, the first Peanuts special to air on the network; with this airing, Peanuts specials have aired on all four major networks. Coincidentally, the first half of the film's original Fox broadcast in 2011 competed directly with a Peanuts special that aired at the same time on ABC ("The Mayflower Voyagers" from This Is America, Charlie Brown). The special aired again on November 23, 2012 (the day after Thanksgiving, so as not to directly compete with the other Peanuts specials) and December 17, 2013.
The program special is particularly notable in that the characters/animation are drawn in a 1950s/early-1960s style, and uses only characters from that time period (including Violet, Shermy, and Patty), except for the inclusion of one later character, Woodstock, and intermediate-era characters Frieda, Faron, 5, 4, and 3 appearing briefly as extras; and even pays homage to the very first Peanuts strip, from October 2, 1950 (when Charlie Brown has a flashback sequence).
The title recalls the 1960s Peanuts phrase "Happiness Is a Warm Puppy," which became a cultural reference.
This special is, by so far, the only Peanuts special to be made in the 2010s, and the only special to be in high definition.
The film was announced by one of the hosts at the 2010 84th annual Macy's Thanksgiving Day Parade when a Snoopy balloon (in his flying ace outfit) passed by, saying "Snoopy fans will be happy to know that next year, a new Peanuts animation will be flying your way."
The last Peanuts special had been in 2006. Craig Schulz, son of the strip's creator, said the intention was to use 1960s style animation. Wildbrain Entertainment found a Korean company to do the work. Schulz also said the majority of the script used the actual strips, supplemented by work by Pearls Before Swine creator Stephan Pastis. Pastis had the idea to focus on Linus' blanket.
After the death of Bill Melendez, the voices of Snoopy and Woodstock were provided by director Andrew Beall, however, in later Peanuts animated productions, some recordings of Melendez were used.
The special starts with Woodstock following holes dug by Linus, who is looking for his security blanket. Charlie Brown is playing baseball with his two friends; Schroeder is playing piano. Lucy keeps trying to hide Linus' blanket, with Linus finding it each time. Linus and Charlie Brown decide to stop Lucy, who then loses the blanket when it flies away with her kite. Linus eventually gets it back. In the meantime, Violet and Patty try to embarrass Pig-Pen with his dirt cloud. The story ends with Linus trying to get his blanket back after Snoopy steals it, shouting "AUGH!!"