Continuity mistake: When Dex is being interviewed in the park, he is holding the basket of baby kittens that he rescued. He is never shown handing the basket to anybody else, but just seconds later, as everyone leaves and Dan arrives in the scene, the basket of baby kittens has suddenly vanished. (00:04:30)Casual Person
Continuity mistake: When Dracula and his architect are going through blueprints of the hotel, Dracula is seen with a coffee in his hand. Mavis spits from the ceiling and it drops down to the table where the blueprints are. When they scan up to Mavis he has coffee, when they scan back to Dracula and his architect there is no coffee in his hand.
Continuity mistake: In the scene where Victor's mother is looking at his chalkboard in the attic, Victor's drawing of Sparky has the word "Alive" above it. Later on in the film, when Toshiaki, Edgar, Bob, Nassor and Weird Girl go into the attic, the word "Alive" is missing from above the drawing of Sparky.
Continuity mistake: At the end of the movie, before the Guardians leave, Jamie rushes over to hug Jack. In the first shot, the top of his head nearly reaches Jack's ribcage. However, in the following close-up shot, Jamie is almost at the same height as Jack's shoulders. (01:27:30)