Trivia: All of the creatures in baby Rapunzel's mobile are referenced later in the movie. The blue bird is the first creature she encounters after leaving the tower (it flies around her head when she sings "completely free"). There is also a white horse (Maximus), a chameleon (Pascal), a yellow duck (The Snuggly Duckling), and a cherub (the old man who dresses like an angel in "I've got a Dream").
Trivia: When Megamind as Bernard is in the library with Roxanne, the book he is reading ("Megamind Unmasked") has a description on the back of a self-help book entitled "The Happiest Me I Can Be". This is the same book that Metroman read (shown later in flashback) that caused him to decide to cease to be a hero. (00:43:30 - 01:08:30)
Trivia: In the scene after Hiccup finally gets Toothless' new tail fin to work, and the two are relaxing after they fly through the fire ball, the two are greeted by a group of tiny dragons. This little dragon was actually what Toothless was originally going to be, as he was in the book, until they changed him to a dragon big enough for Hiccup to ride to suit the movie. (00:46:15)
Trivia: Just before Hannibal, Face and BA break Murdoch out of the hospital by driving the hummer through the wall, watch the credits rolling on the screen of the movie they are watching. Reginald Barclay is the character that Dwight Schultz (the original Murdoch) played on Star Trek: The Next Generation, and the 2nd name ends with "StarBuck", the character played by Dirk Benedict (the original Face man) on Battlestar Galactica. We also see "Thomas", with the surname obscured - likely "Thomas Banachek", a character played by George Peppard, the original Hannibal.
Trivia: When the foursome ski down the mountain and are looking around at the oddly dressed people, someone behind John Cusack says, "Hey Lane, you owe me two dollars". This was a nudge to John Cusack, who played Lane Meyers in "Better Off Dead" and was pursued in the snow by a crazed paper boy shouting "Two dollars!"
Trivia: The Rolls Royce Phantom Coupe that Balthazar drives in this movie was owned by Nicolas Cage himself.
Trivia: Frank Moses' file, seen when Cooper is told he is his next target, gives Frank's date of birth as March 19, 1955. This is Bruce Willis' date of birth. (00:15:00)
Trivia: Make sure to stay after the ending credits to see Will Ferrell and Mark Wahlberg in a restaurant being quite comical.
Trivia: When Hobart falls off the fence when Ramona is mowing the lawn, he yells a Wilhelm scream.
Trivia: Stay after the credits start rolling for a hilarious extra scene.
Trivia: When Jackie confesses that he was orphaned and lived in a group home, this is true for both his character and in real life. Jackie's parents gave him up to the Peking Opera House because they could not afford to raise a child. There he learned how to sing and acrobatics along with his "brothers and sisters."
Trivia: At one point, you can see Craig reading the book "Be More Chill." The book was written by Ned Vizzini, who was also the author of the novel "It's Kind of a Funny Story" on which this film is based.
Trivia: Madame Varcolac's name is Romanian for werewolf.
Trivia: This is a remake of a very famous French comedy, now a classic, Le dîner de cons (available in English as The Dinner Game), itself based on a play which was subsequently altered to conform to the minor changes made when the original movie was filmed.