Continuity mistake: The closeup of Herman's flattened tire on the Dragula shows it resting on a dirt and gravel surface, but as Herman begins to effect repair of the tire it is now resting on a grassy surface.
Visible crew/equipment: Before the police officer removes the Griffin's racing helmet, a film crew member, equipment, and set lights are visible in the helmet's tinted visor.
Continuity mistake: As Lily reads the will to the family, the envelope the will arrived in switches from being held by her at the top of the letter to the bottom of the letter.
Continuity mistake: The close up shot of Herman's hand shows him removing his hand after activating the switch to the secret passage, but the long shot of him and Grandpa shows his hand still on the switch.
Continuity mistake: When Lily is introducing Marilyn to Cousin Grace, Grace's hand holds a biscuit in her hand which changes position as the scene cuts.
Revealing mistake: When Lily throws the ticking apple bomb out of the ship's portal and it explodes, it is dark outside as the scene takes place at night. Stock footage of a depth charge explosion shows daylight.
Continuity mistake: Lily's hand is close to Grandpa's left hand in the long view of it growing fur in the long shot, but the close up shot of Grandpa's hand does not show her hand near his.
Continuity mistake: Lady Effigie's left hand holding the envelope changes position as the shot changes from a long shot to a close up view.
Continuity mistake: When Lily is riding her horse alongside Herman in the Dragula, the background terrain changes whether the scene is a close up of Herman or a long shot of him.
Audio problem: Each time cousin Freddie stomps his feet on the dirt floor while on guard duty, a very loud stomping on a hard surface is heard, not a soft thud that would be heard on on a dirt floor.
Revealing mistake: The stuntman playing Grandpa is obvious when Herman jumps into his arms after scaring the two guys carrying the coffin.
Revealing mistake: Al Lewis and Yvonne DeCarlo's stunt doubles are obvious when Grandpa and Lily mount the horses.
Revealing mistake: The wires used to lift Lady Effigie's chair as Herman lifts the chair to kiss her are visible.
Revealing mistake: Actress Yvonne deCarlo's palms and insides of her fingers do not have her green makeup applied like on her face, arms, etc.
Revealing mistake: The horses shown in close up that Lily and Grandpa are riding are obviously fake.
Revealing mistake: A safety wire is visible as Grandpa hits the low tree branch that knocks him off his horse.
Other mistake: Actor Robert Pine's English accent comes and goes in his scenes with actress Debbie Watson.
Other mistake: The Dragula Herman is driving begins spinning out of control before he hits the oil slick.
Continuity mistake: The oil slick dumped on to the race track by the bad guys disappears after Herman crashes the Dragula into the fence.
Continuity mistake: The huge gash in the left rear tire of the Dragula Herman repairs with his scarf and piece of tape disappears the rest of the race.
