JK Rowling's wildly imaginative terms and rich history are just some of the things that get Harry Potter fans excited about the Wizarding World. Fantastic Beasts And Where To Find Them offered up a lot of new magical material, including all of the new characters, settings and creatures, but it was the Obscurus that caught everyone's attention.
Revealed to be a powerful and dangerous entity, an Obscurus can manifest itself inside a young witch or wizard when their powers have been repressed for a significant period of time. Due to their lack of magical training, the person in question often loses the ability to control the Obscurus, allowing it to lash out against – and sometimes kill – those who have made the child feel downtrodden and worthless.
Since the film reached cinemas and fans learned of the term, many have been keen to know why Harry Potter never became an Obscurial, due to his difficult childhood with his uncle Vernon Dursley and his aunt, Petunia. Now, Rowling has explained…
"An Obscurus is developed under very specific conditions: trauma associated with the use of magic, internalised hatred of one's own magic and a conscious attempt to suppress it," she wrote on her website (via Cinema Blend).
Rowling's explanation certainly makes sense. Before he received his Hogwarts acceptance letter, Harry, who lived the majority of his early life away from the wizarding world, was not even aware magic existed. So he couldn't have felt repressed in regards to his own abilities as he didn't know he even had them.
While "he was scolded for 'making things happen'," around the Dursleys, – who knew he was a wizard and purposefully kept him in the dark about it – "he didn't make any attempt to suppress his true nature, nor did he ever imagine that he had the power to do so," continued Rowling.
It's very likely that the theme of Obscurials will come up again in future Fantastic Beasts outing, given how the most recent film ended. While it seemed like Credence – who was revealed to be an Obscurus in the movie – was killed by aurors, it's already been revealed that Ezra Miller will reprise the role in later movies and "become a main player". Follow-ups movies will have to address how he could survived such an ordeal and whether or not the Obscurus is well-and-truly destroyed or not.