Today WB released a new trailer for Fantastic Beasts: The Crimes of Grindelwald, the second entry in this Harry Potter prequel series. While the trailer mostly focused on characters like Newt Scamander, Dumbledore and Grindelwald, it also offered a glimpse of a character who's been referenced several times in Harry Potter lore - Nicolas Flamel. Assuming you're not a hardcore Potter fanatic, you might not understand the significance of Flamel's cinematic debut.