We fondly remember young Ron's crippling fear of spiders and ability to be eating in many as scenes as possible. Most recently, Grint made his on-stage debut as a drug-dealing bad boy in "Mojo" -- a far cry from the wide-eyed face on the left.
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While Watson has grown up, she still hasn't lost touch with the endearingly dorky Hermione. Watson's latest endeavor is a role in the upcoming Biblical epic, "Noah."
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The actor responsible for everyone's favorite antagonist is soon to be starring in the film "In Secret" as a sickly man with whom his cousin is forced into a loveless marriage. When's Felton going to get to play a good guy?
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If there was any child in the Harry Potter franchise easier to hate than Malfoy, it was Harry's chubby, obnoxious cousin Dudley. Since the series ended, Melling has undergone both weight and fame loss, and he couldn't be happier about it.
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The younger Weasley sister who eventually steals Harry Potter's heart is now set to star in a comedy about small-town beauty pageants.
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The clumsy kid who's notorious for having potions explode in his face is now a full-grown man with stubble. Murray hasn't done any acting since the Potter films, but he's still an active participant in promotional events for the franchise.
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Fans will surely remember the exhilarating and hilariously awkward kiss shared between Harry and Cho in Order of the Phoenix. These days, Leung is a featured character on Hulu's mini-drama "Run."
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Lewis' transformation from the gawky Neville of the early films into a dashing young man gave hope to bumbling adolescents everywhere. Career-wise, Lewis recently took the leading role in "The Rise," a crime movie about revenge and drug kingpins.
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The loyal Gryffindor peer and Quidditch teammate of Harry and Ron hasn't done much acting since the Potter films, although he did appear in an episode of BBC's drama "Broadchurch."
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The Hogwarts student who no one could ever really figure out recently starred in the short "It Don't Come Easy" as a shy wallflower, demonstrating that several of the franchise's actors are partially tied to their Hogwarts counterpart for the foreseeable future.
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One would think the mischievous pair of twins might want to blaze their own trails after being an on-screen duo for so long. Or they could star as Rosencrantz and Guildenstern in an upcoming production of Hamlet and continue developing their excellent chemistry. That works, too.
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What more is there to say about The Boy Who Lived? Radcliffe has begun the impossible task of separating himself from the iconic role by buddying up with John Hamm in the series "A Young Doctor's Notebook."
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Nov. 16 marks the 12-year anniversary of the U.S. release of Harry Potter and the Sorcerer's Stone. As the enormous success of the Harry Potter series continued to grow around the world, previously unknown child actors like Daniel Radcliffe and Emma Watson quickly became household names.
For those of us who grew up with the Harry Potter franchise, it's easy to forget just how young the stars of the films were when they brought Hogwarts to life in 2001. Their bright-eyed expressions would fade to cynicism over years of dances, detentions and Death Eaters.
See also: What Books Would 'Harry Potter' Characters Read?
Many of the actors have undergone notable physical transformations since the days of the first movie, with Harry Melling (Dudley Dursley) slimming down and Matthew Lewis (Neville Longbottom) trading in his baby face.
Take a look at our gallery above for side-by-side comparisons.
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