Rowling actually wrote and published a version of "Fantastic Beasts" for us muggles to read. The book is an encyclopedia of creatures, with a foreword from Dumbledore himself. The niffler and bowtruckle are definitely in it.
Directed by David Yates. With Ezra Miller, Eddie Redmayne, Colin Farrell, Ron Perlman. The adventures of writer Newt Scamander in New York's secret community of witches and wizards seventy years before Harry Potter reads his book in school.