1. It was inspired by an episode of Spaced - the sitcom Simon Pegg wrote with Jessica Stevenson.
2. Almost every actor from Spaced has a part in the film.
Simon Pegg (Shaun), Nick Frost (Ed), and Jessica Hynes (Yvonne) all starred in Spaced. Julia Deakin played Marsha in Spaced and makes a cameo as Yvonne’s mum. Peter Serafinowicz was a regular guest in Spaced and features as Shaun’s housemate Pete. Bill Bailey, another regular guest on Spaced as Bilbo, has a quick zombie cameo. Mark Gatiss, Edgar Wright, Robert Popper, Lucy Akhurst, David Walliams, Paul Kaye, and Paul Putner all made guest appearances on Spaced, sometimes several, and have cameos in the film, too. A scene was written to star Aida, who played Colin the dog in Spaced, but it wasn’t filmed.
6. Quite a few famous partnerships overlap with the ‘other’ gang.
Simon Pegg and Jessica Hynes - Tim and Daisy from Spaced. Lucy Davis and Martin Freeman - Dawn and Tim from The Office. Dylan Moran and Tamsin Greig - Bernard and Fran from Black Books. Julia Deakin and Nick Frost - Mike and Marsha from Spaced.
7. The Winchester was a real pub, until it was closed down and turned into flats.
John and Bernie who run the Winchester are the real names of the landlord and landlady who used to run Simon Pegg’s local pub in Highgate. John used to make toasted sandwiches for regulars, hence the reference to “the Breville out back.” Pegg and Nick Frost used to frequent the pub’s Thursday night quiz, leading to the line “we do the quiz” when Shaun is knocking on the Winchester’s door.
12. All the newsreaders in the film are newsreaders in real life.
16. The film was the first in the Three Flavours Cornetto Trilogy.
In Shaun of the Dead, Ed eats a Strawberry Cornetto (to denote the bloody elements of the film). In Hot Fuzz Angel and Butterman eat Original Cornettos (a blue wrapper, which alludes to the police theme). The World’s End features a green Cornetto (a nod to the alien theme).