Other mistake: When one of the agents is ambushed by the Tooth Fairies he is reduced to a skeleton, with his teeth still visible. However, it was earlier stated that Tooth Fairies start by eating the teeth, then finish off the rest of a body.
Continuity mistake: In the first Hellboy movie, when they first show the BPRD headquarters, it reads "Newark, New Jersey". In Hellboy II, they show what is clearly the same highly distinctive building, but it now reads "Trenton, New Jersey".
Continuity mistake: After the golden army bots awaken, it zooms out to show how big the army is, when they do the prince and princess disappear in the background, then reappear.
Suggested correction: There are two black silhouettes on the background, they should not be black, but still.
Revealing mistake: When Liz, Abe and the Agent are shooting at the Tooth Fairies, the Agent is holding his gun in his right hand, and you can see the fingers of his left hand holding on to the top of the gun's slide while he is firing, showing that it's a prop gun and the slide isn't moving.
Continuity mistake: When Hellboy has been speared in the chest and fallen to the ground, the POV shot of Nuala and Nuada has been turned so their heads are at the right hand side of the frame - from Hellboy's point of view their heads should be to the left.
Other mistake: Dating back to the first Hellboy movie, we know that Abe Sapien has very prominent webbing between his fingers (extending almost to his fingertips). However, in the Troll Market scenes from Golden Army, Abe is wearing snug, full-fingered human gloves, which should be impossible with his webbed fingers.
Continuity mistake: In the scene where Hellboy and Abe are getting drunk by Liz's bed, one shot shows the tab on HB's beer can pointing up. In the next shot, the tab is folded down.
Continuity mistake: When Prince Nuada holds up the golden egg-shaped "Forest God" pod, it's in his right hand. After it opens and he goes to take out the green object, he's holding it in his left hand and takes it out with his right hand.
Suggested correction: Between frames, where the Prince holds the egg with two different hands, there is a shot with Hellboy, long enough for the Prince to switch hands.
He was off camera for 1 second. His left arm was down by his side and his right arm stretched out. Really not enough time to switch hands when he showed no intention of bringing his left arm up and given how slow and deliberate he was moving.
Continuity mistake: When Prince Nuada defies his father, he kills every royal guardsman in a matter of seconds. There are only two guards left, and he kills them, also, before he kills his father. As Nuada kills his father, we see Mr. Wink in the background, fighting a very-much-alive royal guardsman.
Audio problem: At the beginning, when Professor Broom and the young Hellboy are spending Christmas Eve at a military base in New Mexico, Broom insists that Hellboy go to bed, while Hellboy insists that Broom first tell a bedtime story: "Just one, and then I'll go to bed right away, I promise!" Which is an overdub (one of several in this scene). More than once, the young Hellboy's mouth visibly says something very different than is heard in the audio.
Revealing mistake: The sealing caps of the map container have a slightly larger diameter than the container itself. When placed horizontally on a flat surface, the middle should not touch the surface. When the Prince rolls it on the table to reveal the map, the map is CGI.
Suggested correction: The fact the end caps being larger than the middle is correct, however, the middle section's reduced diameter is not the portion that touches when rolled. The middle portion has elevated sections that are what touch the table to reveal the map. When the Prince holds it up before rolling, the elevated portions on the middle are evident. Also, the end caps were not heated like the middle when rolled so no marks are left.
Continuity mistake: When Abe and Hellboy get drunk together, they move into the bedroom where Liz is sleeping. To start off with Hellboy is to the right of Abe and Abe is to the left of Hellboy, but suddenly we get a different view and this time it's a mirror image - Hellboy is to the left of Abe and Abe is to the right of Hellboy.
Suggested correction: The scene starts with Hellboy on the right and Abe on the left as they face Liz. Hellboy and Abe then turn around with their backs turned to Liz. The so called "mirror swap", last glimpse of the two is a now front shot of Hellboy and Abe with each being on the correct side of one another.
Continuity mistake: The amount of flowers on the Bethmoora Goblin's head changes after they visit the Angel of Death.
