Johnny Depp As Gellert Grindelwald In "Fantastic Beasts" Movies, Replaced By Mads Mikkelsen
Johnny Depp seems like a natural fit for the wizarding world of Harry Potter, so it was only natural that fans were happy with his casting. Sadly, when the Depp-Heard scandal hit society, he was practically fired, and Mads Mikkelsen replaced him in the Fantastic Beasts movies. Hopefully, we will see Depp on the big screen soon.
Also, how would anyone be able to tell when some background character in GoT was replaced? There were a ton of them, and they all looked the same.