Trivia: Executive Producer Peter Billingsly has a cameo as the ticket agent at the airport. Peter also played Ralphie Parker in the 1983 movie favorite A Christmas Story.
Trivia: The "old gangster movie" that's on the TV in Harry's apartment is the fictional movie "Angels with Filthy Souls," which was seen in the movie "Home Alone." The director wanted a detective movie for the scene, and said: "We needed something and I hadn’t figured out what I was going to put on that TV yet...Just as a laugh, we got the movie that they shot for Home Alone off of YouTube...We could never beat it!"
Trivia: Nicolas Cage actually owned the Ferrari 550 Maranello that he drives in this movie.
Trivia: The house with the blue door (William's residence) was formerly the home of the movie's screenplay writer, Richard Curtis.
Trivia: The Titans first encounter Slade while he's stealing a power crystal. They mistake him at first for the Marvel character, Deadpool and proceed to argue back and forth about him being Deadpool or not. With him saying that he's not Deadpool, that actually Deadpool should be saying he's not Slade. This is a joke and reference to the fact that the designer of Deadpool based his looks, abilities, and character originally off Slade/Deathstroke because he wanted to draw Deathstroke. Until Deadpool's backstory and personality were changed to what we know him as today.
Trivia: The first MCU movie to feature the word "fuck", when Quill tells Nebula to "open the fucking door", a line that was improvised on-set and kept in because it was so funny. James Gunn anticipated being told to cut it out, but Kevin Feige left it up to Gunn's discretion. Feige said the Russo brothers had a "fuck" in an early cut of Avengers: Endgame, but they "didn't want that to be their legacy, so if you want that to be your legacy, then sure." James Gunn said that just made him even more keen to keep the line in, at which Feige "laughed his ass off."
Trivia: David Graf's wife Kathryn has a cameo in this movie as an airline stewardess.
Trivia: Spike Jonze is uncredited in the movie for his role as Jerry.
Trivia: Even though Frank the pug doesn't appear, there are a couple of references to him. The first one is a big picture of him over J's bed and when J gets pulled over by the cops, there is a billboard advertising for "The Amazing Talking Pug." (00:22:35 - 00:40:25)
Trivia: During the opening musical number, Tracy passes a man on the sidewalk wearing a trench coat who then flashes the crowd; this is John Waters, the writer and director of the original 1988 version.
Trivia: The actress playing Connie has the same surname as her character - Moreau.
Trivia: Fun to spot - In the scene where Eddie Murphy is fighting the big guy, after a while he says, "I know a bitch named Della who hit harder than you." Here, he is referring to Della Reese, whom he fought with in Harlem Nights.
Trivia: Throughout the whole movie, the cars in the backround are Volkswagon Beetles.
Trivia: When Shaun is on the phone to his mum, Ed shouts "We're coming to get you Barbra". This is a tribute to the famous "they're coming to get you Barbra" line from Night of the Living Dead (1968).
Trivia: Mark Knopfler, who composed the music to the Princess Bride, only agreed to do so if Rob Reiner could include the baseball cap he wore in the film Spinal Tap. The director placed the cap in the boy's bedroom, beside the bed.
Trivia: If you look at the poster advertising the play "The Marvelous Marriage," you'll see it was written by Al Funcoot. "Al Funcoot" is an anagram of Count Olaf. This is a common theme in the Lemony Snicket Books.