Magically written. It is written as an extension for the Wizarding World of Harry Potter. The royalties are donated on Rowling's charities: Lumos and Comic Relief. 
It's full of the magical creatures I have once read in Harry Potter series or seen on Fantastic Beasts movies. This is why I love Rowling's books. They are so magical and so minute to detail that feels real. This is one of the books in the Hogwarts first year's syllabus and now we get to read about them like a real book. It was so pure and funny at time. How wittily Rowling writes (as Newt) that some creatures who had already received Muggle press like the unicorns or some creatures like the Dodo bird whom the Muggle believed to be extinct, but in truth, they are Diricawls: a bird that could vanish in a puff of feathers.