Written by JK Rowling herself and set 70 years before the events of the Harry Potter series (insert broken sobs here), the movie adaptation of Fantastic Beasts will be an original story inspired by the Potterverse textbook of the same name. In a press release from Warner Bros, Rowling said,
It all started when Warner Bros. came to me with the suggestion of turning 'Fantastic Beasts and Where to Find Them' into a film. I thought it was a fun idea, but the idea of seeing Newt Scamander, the supposed author of 'Fantastic Beasts,' realized by another writer was difficult. Having lived for so long in my fictional universe, I feel very protective of it and I already knew a lot about Newt. As hard-core Harry Potter fans will know, I liked him so much that I even married his grandson, Rolf, to one of my favourite characters from the Harry Potter series, Luna Lovegood.
As I considered Warners' proposal, an idea took shape that I couldn't dislodge. That is how I ended up pitching my own idea for a film to Warner Bros.
Although it will be set in the worldwide community of witches and wizards where I was so happy for seventeen years, 'Fantastic Beasts and Where to Find Them' is neither a prequel nor a sequel to the Harry Potter series, but an extension of the wizarding world. The laws and customs of the hidden magical society will be familiar to anyone who has read the Harry Potter books or seen the films, but Newt's story will start in New York, seventy years before Harry's gets underway.
Fantastic Beasts is also slated to be developed into other media, including a video game.