At the time this film was in production, only four of the eventual seven books in the series had been published. J.K. Rowling was retained as a consultant on the film, not only to ensure consistency with the first book, but also to avoid conflicts with her vision for the later entries.
The “right to left” shark from Jaws. A number of mechanical sharks were created for different shots in Jaws. This shark only had one side finished for filming, and could angle up and down in the water.