
Character mistake: According to her biography found in the library, Elise was born November 11, 1885, but William Robinson tells Richard that he met Elise when she was 16 years old, in March, 1903, at which time she would have been 17.

Character mistake: At the beginning of the movie, during "Provincial Life", we see a fat lady trying on a hat in a hat store. The sign over the window, in French, reads "Chapeau" (hat). The correct way to identify that store would have been "Chapeaux" (hats) or "Chapelier" (hatter).

Character mistake: Tom states that the Republic of China released fifteen American POWs in 1955. The People's Republic of China (Communist China) might have done so, but the Republic of China (Taiwan) has always been an American ally and would not have been holding any Americans prisoner to begin with.

Character mistake: When Joan is searching the web looking for information on what monkeys eat, there is a section on the screen that reads "The diet of monkeys varies form fruits, leaves." Obviously the correct word for this sentence should be "from" not "form." (00:36:21)

Character mistake: Pygar says to Barbarella, "An angel has no memory." If that's true, how does he recognise Barbarella's touch, her name, his name, his nest, everything?

Character mistake: When Hook has Pan under control, the kids start to say "I believe in you" in turns. The second one, a red haired boy, can't help staring at the camera.

Character mistake: When Tom goes into cardiac arrest, the doctor uses the defibrillator paddles on him, but she uses them whilst the hospital gown is still on him. A defibrillator must be used on bare skin if the electricity is supposed to get through to his heart. (01:08:55)

Character mistake: When Frank opens the present in his office and finds the picture frame from his brother inside, he reads what is supposedly written on the frame out loud: "To Frank, the best brother a guy ever had. Merry Christmas." However, instead of Merry Christmas, it says Love, James.

Character mistake: At the end of the movie when the play is just starting, one of the parents in the front of the audience is holding up a Motorola Razr phone to take pictures but is facing it the wrong way.

Character mistake: Given Billy still remembered and recognized him it seems strange Kate doesn't when she mistakes Daffy for Gizmo.
Suggested correction: Billy spent significantly more time bonding with Gizmo in the first movie - days and days. By contrast Kate had very little actual time with him.

Character mistake: They keep calling the vehicle a milk truck but it says "ice cream" on it. (00:23:55)

Character mistake: Shiwan Khan uses mind control to make Nelson commit suicide. Later, when Lamont is talking to one of his agents, the agent talks about a murder at the museum.

Character mistake: The Mother gave the Man (as Panda the cat) a bowl of vanilla ice cream with whipped cream and apparently some chocolate syrup. Chocolate is toxic to cats and most cats are lactose-intolerant. A mature/adult person should be aware that "people food", in general, is not healthy for cats and certain foods (chocolate and cow's milk) are particularly bad and possibly fatal. (00:27:27)
Suggested correction: This situation is actually more complicated in that the mother was seeing the man (her dead grandson), so wasn't really giving Panda the cat the ice cream. What can't be known is whether Panda as the man could eat ice cream with chocolate syrup and not get sick (e.g, vomit) after he turned back into a cat the same day.

Character mistake: Pretending to be a witch, April says that the song the walkman played was obtained because "I shrunk four incredibly cool guys and I locked them in there." The Barrio Boyzz were five at the song's release. Did she let one Barrio boy go? Was one of the Barrio Boyzz uncool? (00:16:40)

Character mistake: Archimedes says he told Arthur not to pull the sword out of the stone. He didn't, he pointed it out in the churchyard to him instead.
Suggested correction: Archimedes was trying to be helpful when he pointed out the sword so Merlin could take it to the tournament. But after it became a big issue with the rays from heaven and the legend, Archimedes thought he might get in trouble so tried to act innocent by fibbing. It was deliberate and in character, not a character mistake.

Character mistake: When John Henry Irons is arrested, two police officers lay him face-down in order to zip-tie his wrists behind his back. A close-up of Irons' hands, however, reveals that the zip-tie only wraps around his right wrist while crossing about mid-way on his left thumb, meaning that he could easily remove his left hand from the restraint with very little effort. Arresting police officers would never make this mistake in real life.

Character mistake: The batter hit a line drive hit over the second baseman Garcia's head. The pitcher Bass whips his head to his left as the ball goes to right or right center field. The announcer said there's a base hit to left field when it was right field.

Character mistake: Tom Manning criticises Hellboy for using a lighter, (correctly) telling him to use a wooden match instead. But he then lights a match and immediately puts it to the cigar, instead of waiting for the sulphur to burn off and using a pure wood-fuelled flame to light it. He's not as well informed as he thinks.

Character mistake: Inside the loop Barron said the only thing he can't change/shape shift is his eyes but when Emma and Enoch rush in Barron is able to change his whole body, including his eyes.

Character mistake: A priest is holding a globe with a fire to light the globes carried by others. There are two lines with globes approaching the man with the lit globe. The first person in the line from the right has trouble lighting their globe. She starts to return for a second try, but apparently thinks better of it and continues on with the unlit globe.