Continuity mistake: When Wanda and her husband drops off her wolf pups at the kids club, when they are outside her teeth are different shapes and sizes, but when they zoom in they are straight just like her husband's. (00:27:10)
Continuity mistake: During the Macarena scene, when Drac's cape dances, Johnny's DJ disappears.
Plot hole: During the climax with Van Helsing and the Kraken the writers of the film seemed to have forgotten about the powers Dracula has always had. At no point does his super speed or indestructibility ever come into play, he could have easily climbed up to the DJ booth and dealt with Van Helsing in seconds instead of going through the silly DJ battle.
Suggested correction: The kraken was faster and stronger than Dracula, if you watched he kept trying to reach the DJ booth and fight but was stopped each time and nearly crushed. It was said that the kraken was extremely strong and the only thing that could subdue him was a more powerful song than the other.
Continuity mistake: The beginning of the movie shows the year as 1897. Dracula and his group of dudes are on a train going on what seems to be a vacation. Once Van Helsing attempts to kill the monster gang, a series of other previous failed attempts to murder Dracula play out. At the end of the flashback Dracula says it would be great if there was a place for monsters to go, possibly a hotel. The problem is Mavis was born in 1894, and in the first instalment we learned the hotel was being already being constructed when Mavis was a baby three years earlier.
Suggested correction: He had actually said something about being able to go and maybe even get married. He obviously wasn't planning on having weddings at the currently under construction hotel.
He had already been married by this point and Martha had already died, and he didn't believe on second Zings.
Factual error: The female Frankenstein tries to set Dracula up with during the wedding reception is referred to as his "right arm's cousin" but the big arm that looks like Frankenstein is her right arm. (00:08:10)
Suggested correction: Frankenstein wasn't saying she had the other half of his right arm (i.e. his left arm), just that the 2 arms came from 2 people who were cousins.