The former "The Daily Show" actor and comedian was one of several actors and characters announced for the Harry Potter spinoff film via creator J.K. Rowling's Pottermore website on Thursday.
Williams was "The Daily Show's" youngest correspondent at 22-years-old before departing the show to focus on a new series for Comedy Central in June.
The upcoming sequel will feature several characters that have been referenced in previous entries in the Harry Potter series.
Actor Brontis Jodorowsky will appear in the film as Nicolas Flamel, a character mentioned in the first book in the series "Harry Potter and the Sorcerer's Stone" as the alchemist who discovered the Elixir of Life.
Derek Riddell will appear as Torquil Travers while Poppy Corby-Tuech will play Rosier, a pair of characters named as Death Eaters who served the series' main villain Lord Voldemort.
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