"Easter eggs", or small references to previous works of the Castle cast, appear frequently in episodes. At the Paley Center's "An Evening with Castle"in March, 2010, Nathan Fillion said the show's cast and crew are fully aware of how much the audience enjoys these nods and therefore try to work them into episodes as appropriate. The most common type of Easter egg is a nod to Nathan Fillion's previous role of Captain Malcolm Reynolds on the short-lived series Firefly, which ran for less than a full season, but developed a tremendous cult following.
Firefly Easter Eggs[edit]
- That would be a Very Special Brand of Hell
- Castle: Always Buy Retail
- Firefly: "Our Mrs. Reynolds"
- Criminal Mastermind
- Castle: Home is Where the Heart Stops
- Firefly: "Ariel"
- Space Cowboy / Captain Mal Reynolds / Captain "Tightpants"
- The background MUSIC is reminiscent of Firefly when Richard Castle makes his appearance wearing a Halloween costume very similar to that worn by Captain Malcom Reynolds from Firefly
- Alexis Castle asks what he is supposed to be and he says "space cowboy". She then asks "Didn't you wear that 5 years ago?" (around the time when the movie Serenity came out). He confirms this, but protests that he "likes it."
- Castle: Vampire Weekend
- Firefly: Firefly (the series) and Serenity (the movie)
- Castle: Vampire Weekend
- Firefly: "Out Of Gas"
- Shindig
- Castle: Vampire Weekend - Ryan refers to Castle's Halloween Party as a Shindig
- Firefly: "Shindig the episode
- Zac Efron
- Castle: Vampire Weekend - Alexis is caring for her "egg child" and Castle asks if his name is "Zac Eggfron"
- Firefly: "Safe -Zac Efron plays a young Simon Tam
- Crow
- Castle: Vampire Weekend - Name of the first victim
- Firefly: "The Train Job" - the henchman for Adelai Niska (Crow gets kicked by Mal into the engine of Firefly)
- Two by Two, Hands of Blue
- "Yea, you better run"
- Castle: The Mistress Always Spanks Twice (Beckett teases Castle then turns and leaves)
- Firefly: "Trash" when Saffron leaves him naked in the desert.
- "I was aiming for his head!"
- Castle: Boom
- Firefly: "The Train Job"
- speaking Chinese (Castle says: "that was from a show I used to love")
- Castle: Close Encounters of the Murderous Kind
- Firefly: any episode
- Serenity
- Castle: Setup (Martha Rodgers asks Castle "You've never heard of the Serenity?)
- Castle: Murder, He Wrote (Castle comments on "the serenity" being something he loves about his Hampton's house)
- Firefly: any episode (the name of Mal's spaceship is Serenity)
- Vera
- Castle: The Blue Butterfly (Name of gangster's moll)
- Firefly: Our Mrs. Reynolds (Name of Jayne's favorite weapon)
- Ms. Frye
- Castle: The Final Frontier (The last name of the killer)
- Firefly: any episode (The last name of the Serenity's engineer, Kaylee)
- Max Rennard/Mal Reynolds
- Castle: The Final Frontier (Max Rennard is the captain of the spaceship in the fictional television show Nebula 9)
- Firefly: any episode (Mal Reynolds is the captain of the spaceship in Firefly)
- Reavers/Creavers
- Castle: The Final Frontier (Creavers are the alien race of the fictional television show Nebula 9 and who will "chew your face off then feed your organs to their young.")
- Firefly: any episode (Reavers are a cannibalistic alien race)
- Lt. Chloe/Zoe
- Castle: The Final Frontier (Lt. Chloe was the second in command on the spaceship featured in the fictional television show Nebula 9)
- Firefly: any episode (Zoe was the name of the second in command on the Serenity)
- "12 episodes aired a decade ago"
- Castle: The Final Frontier (The run of the fictional television show Nebula 9)
- Firefly: any episode (11 episodes aired 10 years before The Final Frontier)
- "That Joss Whedon show"
- Castle: The Final Frontier (Castle references Firefly as an example of "good sci-fi")
- Firefly: any episode
- "Ariel"
- Castle: The Final Frontier ("Lt. Chloe hasn't teleported back from Ariel's moon - quote during the fan experience)
- Firefly: Ariel (9th episode where they break into a hospital in Ariel City)
- "Shiny"
- Castle: Lucky Stiff (Becket tells Oz the drug dealer she likes to feel Shiny)
- Castle: The Final Frontier (Castle when he finds out there has been a murder at SuperNovaCon)
- Firefly: most episodes (said by crew members many times to mean nice or ok)
Other Easter Eggs[edit]
- Vampire Weekend - At the end of the episode, Castle hosts a Halloween party for his friends at the 12th precinct. Detective Javier Esposito wears a Desert Storm military outfit, which is a nod to Jon Huertas's previous role as a soldier the miniseries "Generation Kill" and Detective Kevin Ryan wears a surgeon costume, a nod to Seamus Dever's former role as Dr. Ian Devlin on the long-running soap opera General Hospital.
- Close Encounters of the Murderous Kind - The episode also included numerous allusions to The X-Files since many of the Castle crew worked on that show. Castle whistles the theme a couple times in the episode.
- In Tick, Tick, Tick, Martha is watching the pilot episode of the TV series The Incredible Hulk; the scene shows Susan Sullivan as a scientist describing Hulk's appearance to someone off-screen.