7 Harry Potter Fan Theories J.K. Rowling Debunked (And 3 She Approved)

2. The Snake Harry Frees In The Philosopher's Stone Is Nagini

The Theory: It's a real shame that this theory isn't true: it's simple, adds an extra bit of flavour to Harry's pre-Hogwarts years, and would have meant that his journey started and ended with the creepy giant snake. How poetic.

Early on in the first book/movie, Harry visits a zoo with the Dursleys as a part of Dudley's birthday celebration. While there, he unwittingly releases a giant boa constrictor, which slides away and is never seen again. Or so we thought.

Many fans have talked about the idea that the snake was actually Nagini - one of Voldemort's Horcruxes - who we officially meet in The Goblet Of Fire. There isn't much evidence backing this concept up (besides the fact that they're both huge snakes) but because we don't know what happened to the snake after the zoo incident, there was a slim chance this theory was true.

The Debunking: Another great idea this one, but recently, Rowling put a definitive end to any and all speculation.

Additionally, others have pointed out that the boa constrictor is not venomous, while Nagini is, so the answer was under our noses all along. The true story of Nagini's origin will actually be revealed in Fantastic Beasts: The Crimes Of Grindelwald next month, so we don't have long to wait!