First up, Shaun Of The Dead:
1. The first zombie Ed and Shaun find in their garden is Mary, the checkout girl from the film's opening credit montage.
2. There's a comic written by Frost and Pegg called "There's Something About Mary" that details how she ended up in the garden.
3. Shaun yells at Ed for using "the zed word" (zombie), which is a reference to the fact that most famous zombie films, including Romero's Dawn Of The Dead, no one ever uses the word "zombie."
4. The zombie in the yellow hat is actually Tyres, the raver bike messenger from Spaced*, the sitcom Edgar Wright, Simon Pegg, and Nick Frost did before Shaun Of The Dead.
*Which, if you haven't seen, you should. You're not going to get a few of these Easter eggs without having seen Spaced. Also, it's a terrific show.
5. Okay, so this one is a little complicated, but when Shaun and his gang meet the other gang in the alley there is a very funny joke going on:
The first three pairs in the gang all played opposite each other on other British sitcoms:
• 6 + 7: Simon Pegg and Jessica Hyne played Tim and Daisy on Spaced.
• 3 + 8: Lucy Davis and Martin Freeman played Dawn and Tim on The Office.
• 4 + 18: Dylan Moran and Tamsin Greig played Bernard and Fran on Black Books.
6. The word "fuck" is used 77 times.
7. In the beginning of the movie, Shaun's roommate Pete tells Ed if he "wants to live like an animal, he can live in a shed." At the end of the movie, well... he does.
8. The scene where Ed tries to cheer up Shaun actually foreshadows every plot point.
You can watch the clip here.
9. And of course, Shaun Of The Dead, features a red Cornetto ice cream, red being for blood and zombies.
Moving on to Hot Fuzz:
10. Simon Pegg's character "Nicholas Angel" is named for music supervisor Nick Angel, who worked on Shaun Of The Dead, Hot Fuzz, and The World's End.
11. The fictional "Norris Avenue" in the town of Sandford is named after action movie star Chuck Norris.
12. The town of "Sandford" is named after the stock town name used in British police training exercises.
13. Knife-wielding Santa Claus is actually an uncredited Peter Jackson.
14. And Nicholas Angel's CSI girlfriend is an uncredited Cate Blanchett.
15. The evil townspeople in Hot Fuzz all have pretty evil last names: Hatcher, Skinner, Roper, Reaper, Blower, Messenger, and Shooter.
16. Nick Frost's Danny asks Nicholas Angel a lot of questions about what action movie cop moves he's done before, like jumping through the air, all of which come true in the second half of the movie.
17. The ice cream flavor shown in Hot Fuzz is blue, which symbolizes police.
And lastly, The World's End:
18. The poster for The World's End is actually a reworking of a poster for '70s alien invasion movie End Of The World.
19. The pub sign for The King's Head is actually a picture of Simon Pegg, who plays the character of "Gary King" in The World's End.
20. This specific type of bar arcade game appears in pubs in all three Cornetto Trilogy movies.
21. In the beginning of The World's End, Simon Pegg's Gary is in a support group, if you look directly next to him you'll see the actress who played Zombie Mary.
22. The film opens with Primal Scream's "Loaded" and at the very end when Gary and Andy are confronting The Network, Gary drunkenly recites the opening lines.
23. The five friends all have royal court-inspired last names: (Gary) King, (Andy) Knightly, (Peter) Page, (Steven) Prince, (Oliver) Chamberlain.
24. Like Ed's cheer up speech in Shaun Of The Dead, and Danny's action movie question in Hot Fuzz, the pubs in The World's End foreshadow the film's plot.
• The first pub they go to is The First Post.
• The second pub they go to is The Old Familiar which looks identical to The First Post.
• The meet the town's famous crazy old man Basil in The Famous Cock.
• The fight the robot teenagers in The Cross Hands.
• The see local drug dealer Reverend Green in The Trusted Servant.
• The fight the robot twins in The Two-Headed Dog.
• The gang is tempted by robot women at The Mermaid.
• Gary King slams his head against the wall at The King's Head.
• A car is driven through The Hole In The Wall, which makes an actual hole in the wall.
• And the world ends at The World's End.
25. The flavor seen at the end of The World's End is a mint Cornetto, symbolizing aliens.
26. All of the films feature the "never taken a shortcut before" line.
27. Which, of course, leads to the fence gag.
28. And lastly, ending where it all began, all of the main cast for the 14-episode run of Spaced have made it into a Cornetto Trilogy film.
• Simon Pegg - Tim in Spaced, Shaun in Shaun Of The Dead, Nicholas Angel in Hot Fuzz, and Gary King in The World's End
• Nick Frost - Mike in Spaced, Ed in Shaun Of The Dead, Danny in Hot Fuzz, and Andy in The World's End
• Jessica Hynes - Daisy in Spaced, Yvonne in Shaun Of The Dead
• Julia Deakin - Marsha in Spaced, Yvonne's Mum in Shaun Of The Dead, Mary Potter in Hot Fuzz, and B&B Landlady in The World's End
• Mark Heap - Brian in Spaced, "Publican 7" in The World's End