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: 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: The "Bride in Black" is played by a man wearing women's clothing. This was done so that something would feel "off" about the image of the ghost. At the time, the character was intended to be female. However, when the creators later reused the character for the sequel and added in a backstory, they worked the fact that the character was played by a male as part of his backstory - it actually is a man who masqueraded as a woman as a disguise to lure in victims.
Trivia: During the film's climax, a young boy in an Iron Man mask is shown standing up to one of the Hammer drones with Iron Man swooping in and destroying the drone and giving the kid the credit. Following Spider-Man's inclusion in the Marvel Cinematic Universe, a fan theory suggested the young boy was Peter Parker, which Marvel Studios President Kevin Feige and Spider-Man actor Tom Holland would later retroactively confirm.
Trivia: The real Penny Chenery, the owner of Secretariat, makes a cameo as a spectator at the Belmont Stakes.
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: Actress Mila Kunis was actually recommended by Natalie Portman for the part of Lily.
Trivia: The movie was originally scripted with a male lead and Tom Cruise was approached to play the title character. Ultimately, he backed out and the script was rewritten with a female lead and Angelina Jolie took the role.
Trivia: Domhnall Gleeson, who plays Bill Weasley, is the son of actor Brendon Gleeson (Mad-Eye Moody).
Trivia: The CGI wolves have no genitalia in the Eclipse movie because they needed to maintain the PG-13 rating.
Trivia: In a shot of Zeus sitting on the throne, Emma Thompson, in costume as Nanny McPhee, is actually hiding behind the throne - they were filming next to each other. The story was related during an interview - she sneaked on set during a break, sat on Liam Neeson's lap and said "I think you've been a very naughty boy". He suggested she stay when filming resumed, as the shot wasn't going to be on him anyway, but she didn't want to throw off Ralph Fiennes, so hid behind the throne to get out of the way, and a shot of it with her hidden behind, unseen, is in the movie.
Trivia: After Robin and his men arrive in Nottingham, Will Scarlet and Little John are in a tavern admiring the women - Will advises his comrades not to go for the most beautiful woman, but to go for her less attractive friends, thus ensuring success. This is the expression of Game Theory, as explained by John Nash (also played by Russell Crowe) in A Beautiful Mind.
Trivia: Makeup artist Rick Baker has a cameo appearance in this film. He's the man who whistles to his comrades who are approaching the gypsy camp then a few seconds later, gets killed by the werewolf.
Trivia: This was Tony Scott's final feature film before his death in 2012.