Fantastic Beasts: Crimes Of Grindelwald Trailer Confirms A Major Nagini Fan Theory

The final trailer for Fantastic Beasts: The Crimes of Grindelwald has, at last, revealed the identity of actress Claudia Kim's character -- something that has been kept tightly under wraps until now.

In the trailer, Kim appears in a large cage before transforming into a giant snake for a crowd of surprised onlookers. And in case that wasn't enough of a clue, Ezra Miller's Credence Barebone can just about be heard whispering a single word pre-transformation: "Nagini." Final confirmation comes from Kim herself in an interview with Entertainment Weekly, expressing visible excitement to finally let the cat (or, uh, snake?) out of the bag.

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Nagini's inclusion provides a strong link between the Fantastic Beasts saga the original Harry Potter series, where no real indication was ever given that Voldemort's favorite pet was ever anything other than an unusually large green snake. The pair are thought to have had their meetcute in the forests of Albania after Voldemort's near-fatal encounter with baby Harry left him drifting and bodiless, reduced to possessing animals for survival. Naturally, the villain's Parseltongue ability (speaking the language of snakes) and self-coveted status as Salazar Slytherin's heir bonded the two of them quickly. Her venom was later used by Peter Pettigrew to brew a life-sustaining concoction of dark magic while his master inhabited a temporary human body.

After his return to power, Nagini became Voldemort's most trusted companion and efficient assassin. She was even able to wear the body of Bathilda Bagshot like a puppet and almost lure Harry and Hermione to an early grave in The Deathly Hallows. The Dark Lord later rewarded her loyalty to him by making Nagini his final Horcrux, meaning she would inadvertently play a key role in his final downfall -- slain with the sword of Godric Gryffindor by Neville Longbottom at the Battle of Hogwarts, but not before taking the life of Severus Snape.

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Confirmation of Nagini's involvement in The Crimes of Grindelwald brings months of feverish speculation from Potterheads to an end. The theorizing began when early plot details mentioned a circus location with Kim's unnamed character as one of the "featured attractions."

The idea that the type of attraction she'd be was a shapeshifting human cursed to one day become a beast forever -- known as a Malendictus -- gained weight from a shot in the first Crimes trailer showing a poster for "The Enchanting Snake Girl" hanging at the entrance of the Circus Arcanus -- a tagline first seen in similar promotional material for the "museum of oddities" in Fantastic Beasts and Where To Find Them. The first cast photo from Crimes also subtly reinforced her hidden serpentine identity by depicting the South Korean actress in snakeskin-printed clothing.

Until now, marketing for the movie continued to keep everything else about the character a secret, fuelling speculation that this wasn't just any snake girl but, in fact, was the future familiar of He-Who-Must-Not-Be-Named. This means that Crimes will not only flesh out the backstories of big Potter players like Dumbledore and Grindelwald but Nagini's too, which has coincidentally been as mysterious in the world of Harry Potter as her role in the Fantastic Beasts sequel has. Very little was known about Nagini's life prior to her appearance in The Goblet of Fire, a life which we now know spanned about 70 years.

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"It will be so interesting to see another side of Nagini," Kim told EW. "You've only seen her as a Horcrux. In this, she's a wonderful and vulnerable woman who wants to live. [...] She is bound to [permantly] transform at some point to a beast so she feels this pressure that the clock is ticking." There's clearly a lot more to Nagini than fans ever knew, including, as Kim hinted, other unique forms of magic. "She has powers that are yet to be explored. I can't confirm she has powers as other wizards have. And she doesn't have a wand."

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