Continuity mistake: At the very start the priest holds up a crucifix and says the men will need them. The way the crucifix is held changes instantly. (00:02:00)
Continuity mistake: At the beginning when Broom is bandaging his wound, a soldier asks him about Hell. Broom turns to look at him, but in the next shot is facing forward again. (00:10:25)
Continuity mistake: When scraping the snow off thee wall at the start, the amount of snow changes drastically and instantly. The lines of the engraving are clear of snow instantly. (00:14:30)
Continuity mistake: When Professor Broom is feeding that thing in the tank rotten eggs, you see him pick up one egg and put it in the tube. When he pushes the tube up in the next shot, you see more than one egg in the tube. (00:20:00)
Continuity mistake: In the truck on the way to the library, Abe rises and says, "Outside...with her," and gestures. In the next shot, he's hunched over. (00:25:50)
Continuity mistake: Hellboy's oversized "Samaritan" revolver is shown to only hold 4 rounds. Yet he fires more than 4 times without stopping to reload during his fight with the first Sammael creature in the museum. (00:29:50)
Continuity mistake: When Hellboy punches the car in the street, watch closely: he knocks the bumper off, it moves in the direction of the car, yet it never hits the ground. (00:32:30)
Continuity mistake: Kroenen kills the two museum guards on the balcony and they flip as they fall. The shot on Kroenen shows both landing facing up (use slowmo to see ties) and they bounce with their toes pointing up. In the next shot showing Kroenen and the other guards, the dead guards are facing down. (00:41:35)
Continuity mistake: When Hellboy is walking at one point, holding his gun up in his left, gloved hand (just after one of the agents has said "This place is like swiss cheese"), watch the frame. It switches suddenly so his right hand (the stone one) is his left, and he's holding the gun in his "right." (00:59:40)
Continuity mistake: In the scene where Abe Sapien is investigating the cistern for Sammael's eggs, the cord holding the reliquary Hellboy gave him is cut and it falls out of reach. A few shots later, when Abe is frantically swimming away from Sammael, the charm can be seen still attached to his right-hand wrist, following his movements as if still attached to him. (01:01:30 - 01:02:30)
Continuity mistake: After Liz arrives at BPRD, Myers gives Hellboy chili and tells him that nachos are on the way. A dark cat is walking up to Hellboy's left side on the bed. In the next shot, the cat in that place is black-and-white and facing away from the camera. (01:08:35)
Continuity mistake: When Liz goes to tell Hellboy that she is going out with Myers, her arms change from at her stomach and shoulder to at her sides between a shot from behind and the next front shot. (01:09:00)
Continuity mistake: On their date Myers tells Liz that Hellboy loves her. She looks up into his face, but in the next shot she's looking down again. (01:11:20)
Continuity mistake: When Rasputin is talking to the professor about the evil in him, his hand ripples. From the front, his small finger is mostly straight, but in the shot behind, it's mostly flexed. Cut back and it's straight again. (01:17:40)
Continuity mistake: Hellboy tosses Dr. Manning through the quickly-closing door to escape the pendulum on the bridge - he barely makes it under. Hellboy then spends thirty seconds dodging the pendulum, but when he dives for the door it's still closing at the same point and speed - just enough for him to pass. (01:30:55)
Continuity mistake: In the chapel at the end, Ilsa punches Myers and looks down to her right at him. Next shot is over Hellboy's shoulder, and she's still looking down in the background. Cut back to her for several lines and she's looking up and to her left. (01:41:00)
Continuity mistake: In director's cut dvd edition, toward the end of the movie, when Hellboy hits Kroenen in a head, and says, "You killed my father, your ass is mine," Kroenen's left side of a mask changes from being damaged to intact, than damaged again from different angles. (01:43:20)
Continuity mistake: At the end of the movie, when Hellboy and Liz are talking and Hellboy says, "Hey, you on the other side, let her go...", he raises his head and their heads are close to each other. When it cuts, their heads have moved further away from each other. (01:52:30)
Continuity mistake: After Hellboy falls on the dumpster and sees Rasputin walking toward him, there is a smear of blood on HB's lower lip. It cuts away for a second to show him pick up his gun, and when you see Hellboy again, the blood is gone.
Continuity mistake: At the end when Hellboy is carrying Liz off the altar she hasn't got a top on. Later after Hellboy kills the behemoth she has got a top on.
Chosen answer: According to the comic books, his name is Anung Un Rama, or 'World Destroyer, The Great Beast.'