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: The creature that hunts down the Doctor before being shot down by the Sniper girl is actually the original design of the Predator that was scrapped during Predator 1 due to issues with the costume and the jungle. The original Predator was supposed to be very slender with backwards knees and long arms, but because of the jungle setting, it was scrapped because the director was unable to make the costume work properly.
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: Domhnall Gleeson, who plays Bill Weasley, is the son of actor Brendon Gleeson (Mad-Eye Moody).
Trivia: The two 'disc jockeys' in the soundbooth of the 'End of Line' club are actually Daft Punk, the French group that created the movie's soundtrack.
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: Sylvester Stallone sustained 14 injuries during filming, including breaking a tooth, rupturing his ankle and getting a hairline fracture in his neck that required the surgical insertion of a metal plate. He even had bronchitis and shingles during the shoot.
Trivia: The Rolls Royce Phantom Coupe that Balthazar drives in this movie was owned by Nicolas Cage himself.
Trivia: Alice's impending battle on the "frabjous day" with a creature referred to as a "Jabberwocky" is a central plot point, and refers to Lewis Carroll's famous poem "Jabberwocky," from which other characters in the film, such as the Jubjub bird and Bandersnatch, are derived. However, the titular creature of the poem "Jabberwocky" was NOT a Jabberwocky, but a Jabberwock. For whatever reason, the writers of the film chose to call it by the [admittedly similar] title of the poem instead of the actual name of the creature. (For the full text of the poem, see http://www.jabberwocky.com/carroll/jabber/jabberwocky.html).
Trivia: When Hobart falls off the fence when Ramona is mowing the lawn, he yells a Wilhelm scream.
Trivia: When a pine cone falls out of a tree and hits Yogi in the eye, a "Wilhelm scream" can be heard.
Trivia: When Eli and Solara are in his room for the night there is a movie poster on the wall behind them for a similar post apocalyptic movie. "A Boy and His Dog". In Eli the survivors protect themselves from the sun's rays and in "A Boy and His Dog" they flee underground to hide from the sun.
Trivia: Terry S. Mercer, the helicopter pilot that rescues Aron at the end of the film, is the actual pilot that rescued the real Aron Ralston.
Trivia: The scene when Ramona delivers the package to Scott and he signs for it, he takes the package and throws it over his shoulder into the trash can, some several feet behind him. In the outtakes reel, they show that no special effects were used. Michael Cera made the shot over his shoulder on his 33rd attempt.