Mistakes
The "Great Terror" turns out to be a giant goose, but you see in the shot inside the castle that its footprint is not webbed, even though geese have webbed feet. See more...
Movie Mistakes blog
Popular blog posts:
Top 15 biggest Harry Potter film mistakes
The 10 biggest mistakes in Iron Man 1 & 2
30 Biggest mistakes in the Star Wars movies
Other great sites
Puss in Boots (2011)
starring Antonio Banderas, Billy Bob Thornton, Salma Hayek, Zach Galifianakis (add more)