The Harry Potter Spinoff "Fantastic Beasts and Where to Find Them" has developed into a trilogy even if the original plan was for a one-off. Author J.K Rowling said readers have only Warner Bros. CEO Kevin Tsujihara to blame.

The book was originally published as a standalone in 2001 separate from the world of Hogwarts. It's about the book that Harry Potter and other freshmen in Hogwarts written by a magizoologist Newt Scamander. A magizoologist, said popcrush.com, is a scholar who studies magical creatures.

However, the Harry Potter spinoff now ended with three "megamovies," the New York Times said.

Even Warner Bros. CEO Kevin Tsujihara was proud of the fact that he managed to persuade J.K. Rowling into writing two other books to complete the Harry Potter spinoff "Fantastic Beasts and Where To Find Them."

"When I say he made Fantastic Beasts happen, it isn't P.R.-speak but the literal truth," J.K. Rowling told the Times. "We had one dinner, a follow-up telephone call, and then I got out the rough draft that I'd thought was going to be an interesting bit of memorabilia for my kids and started rewriting!"

The Harry Potter spinoff, although required reading at Hogwarts, doesn't really reference any of the Harry Potter characters, said IGN.

The world of "Fantastic Beasts and Where to Find them" is set about 70 years before Harry Potter even existed. The book as well as the Harry Potter spinoff focuses on Newt Scamander and his adventures in going about identifying the magical beasts.

The website IGN added that the book was written by J.K. Rowling to raise money for the Comic Relief in 2001. The Comic Relief, despite its name, was founded in 1986 by comedian Bob Zmuda in order to help those who are in need.

Emma Watson earlier told MTV that she's willing to do a cameo for the Harry Potter spinoff if the studio will ask her to.