Although Shaun of the Dead appeared to have nothing in common with the Coen Brothers, star and co-writer Simon Pegg cited the directors as huge influences on the film. Shaun of the Dead was the first installment of Edgar Wright’s Three Flavors Cornetto Trilogy (along with Hot Fuzz and The World’s End). The zombie movie paid homage to An American Werewolf in London, Night of the Living Dead, and other classic horrors that served as inspiration for the film. However, the inspiration that the Coen Brothers supplied is less obvious.
Simon Pegg, who played the underachieving Shaun, revealed in a 2017 interview that 1987’s Raising Arizona was a film that he and Edgar Wright bonded over (via BFI). Raising Arizona was written and directed by Joel and Ethan Coen and starred Nicholas Cage, Holly Hunter, and John Goodman. The similarities between the film's brand of zany comedy and Shaun of the Dead's humor are not glaringly obvious. However, Pegg explained how Raising Arizona’s script and camera work were a key reference for himself and Wright:
“…there were jokes in the way the camera moved and jokes in the way the camera rhymed with itself, thematically and structurally […] the idea of creating cyclical dialogue and rhyming scenes with each other [for Shaun of the Dead] all came from this film.”
Wright and Pegg took these theories that they extrapolated from Raising Arizona and used them throughout the Cornetto Trilogy. In Shaun of the Dead, the most common use of cyclical dialogue was “you’ve got red on you.” There are also numerous instances of rhyming scenes, such as the two one-shot sequences of Shaun visiting his local shop. Pegg explained that the Coens used cyclical dialogue and rhyming scenes to create verbal and visual jokes. What he didn’t explain was that in Shaun of the Dead, they also used these techniques to display character growth.
In Raising Arizona, the phrase “okay then” is repeated in various contexts. In one instance, an old man says it after being told to shut up while being held at gunpoint. In another, a priest says it after Hunter’s Ed and Cage’s Hi say “I do” at their wedding. The nonchalance of the line delivery was echoed in Shaun of the Dead whenever the line “you’ve got red on you” was said. Again, the change in context delivered the laughs. At first the “red” is just ink on Shaun’s shirt. Later in the film, it's blood all over his face and body. However, Shaun of the Dead uses cyclical dialogue for different purposes, too. Early in the film, Shaun and Ed check for zombies outside their house. Ed asks directly, “Any zombies out there?" to which Shaun insists that Ed doesn't say “the z-word.” As Ed grows from a lazy and poor friend into one that listens to Shaun, he later shouts at David, “We’re not using the z-word!” The use of repeated dialogue enforces comedy and character growth.
The rhyming scenes present in Coen Brothers' movies are also used to the same effect in Shaun of the Dead. Multiple times, Shaun is hit by flying objects, such as pork rinds in the opening scene. While things hitting Shaun in the face are funny enough, it also demonstrates his failure to take action in his life. Like being hit in the face, this passiveness always comes back to hurt him. After Shaun grows into his role of leadership in the film, another pack of pork rinds is thrown his way. This time he catches it, showing that he has become a man of action.
These techniques that Wright and Pegg learned from the Coen Brothers are used in Shaun of the Dead and throughout the Cornetto Trilogy. The most famous running gag is the characters trying (and often failing) to jump over garden fences. By creating cyclical dialogue and scenes that run throughout all three films, they created a trilogy that was not bound by plot, but by a visual style that repeated itself - a style that was inspired by the Coen Brothers.