1. In Big Mouth, you can see a poster for a Get Out pastiche called Stay Out. Jordan Peele actually voices a character in the show.
2. In Parks and Rec, Jerry shows Tom his ID, which reveals that his name is Garry. In the following episode, it’s revealed that his name is in fact Garry.
3. In The Good Place, the safe Jason buys is from the Swanson Safe Company, a nod to Ron Swanson from Parks and Rec.
Michael Schur is the creator of both The Good Place and Parks and Rec.
4. Also in The Good Place, you can see a Dennis Feinstein perfume ad, another nod to Parks and Rec.
5. In That ’70s Show, one of the doctor’s names is K. Ashton, the inverse of Ashton Kutcher’s name.
6. In Bob’s Burgers, Bob’s ice cream machine is eaten by a mechanical shark, and in the next episode it’s back in the restaurant but with teeth marks.
7. In Friends, Joey and Ross reminisce about a beer they drank while in England. Later in the series, you can spot a six-pack of it on top of Joey’s fridge.
8. In The Office, Dwight is seen reading a newspaper that shows that the city is looking for people to paint murals, a job Pam is later hired to do.
9. In an episode of Roseanne, each member of the Connor family is seen wearing the same chicken T-shirt, which became a running gag on the series.
10. In Modern Family, you can see the commercial Lily was almost cast in playing on the TV behind Phil.
11. In the episode of It’s Always Sunny in Philadelphia called “The Gang Goes to Hell,” their hotel room number is “H666.”
12. In The Office, Dwight puts Creed’s name in quotes on his management hierarchy chart, suggesting that he always knew “Creed” was a false identity.
13. In Brooklyn Nine-Nine, it’s revealed that the new captain is “too stupid to work the blinds.” Later in the episode, you can see the blinds in the background aren’t closed properly.
14. In The Office, the Scranton branch is located on Slough Ave. The UK version of The Office was set in Slough, Berkshire, England.
15. Champion from Parks and Rec makes an appearance in an episode of The Office.
16. In a flash-forward on How I Met Your Mother, you can see a newspaper clipping behind Marshall implying that he eventually captured the Loch Ness monster.
17. In Seinfeld, this is shown on the fridge when Jerry is trying desperately to remember his girlfriend’s name.
18. In New Girl, this news segment is a nod to Zooey Deschanel giving birth to her daughter, Elsie Otter.
19. In Arrested Development, Buster’s loss of his arm is foreshadowed when he sits on this bus bench.
20. In How I Met Your Mother, the newspaper with Zoey’s article also mentions Dowisetrepla and the Cockamouse.
21. And finally, in Parks and Rec, one of the trick-or-treaters at Andy and April’s is dressed as Chris Pratt’s Marvel character, Star-Lord.