The first, ancient edition of Fantastic Beasts was commissioned in 1918 by the publishing house Obscurus, specifically by the honorable Mr. Augustus Worme, who kindly asked me if I was interested in writing an official and complete index of magical creatures. At that time, I was merely a simple employee of the Ministry of Magic, and I was thrilled by the idea that not only would I supplement my meager income of two Galleons a week, but I would also spend my holidays traveling and searching for new species of animals all over the world. Now, Fantastic Beasts has reached fifty-two editions. This introduction aims to answer some of the most frequently asked questions that have been arriving in my mailbox every week since the first edition in 1927. And I begin with the most important, and most fundamental, of these questions. What is a magical creature?

The definition of the term "magical creature" has been a subject of disagreement for centuries. Although it may seem strange to some beginners in Magizoology, the best approach to tackle the problem is to briefly examine three types of magical beings. Werewolves spend most of their lives as ordinary humans (either wizards or Muggles). Once a month, however, they transform into bloodthirsty four-legged beasts, with murderous intentions and no human consciousness. The habits of Centaurs are not human. They live in the wild, do not wish to wear clothes, prefer not to communicate with wizards or Muggles, and yet their intelligence is equal to all. Trolls have a humanoid appearance, walk on two legs, utter some words, and yet are less intelligent than the dumbest Unicorn. They have no innate magical ability, except for a terrifying and unnatural physical strength.