Douglas Petrie is an American TV producer, screenwriter, and director who came to prominence for his work on the cult action-fantasy series "Buffy the Vampire Slayer. " Petrie began his career in television in the early 1990s as a writer on the Melissa Joan Hart-starring tween comedy "Clarissa Explains It All." After a brief stint in feature films, writing the screenplay of the children's action comedy "Harriet the Spy" (based on the beloved 1960s children's novel by Louise Fitzhugh), Petrie joined the writing staff of "Buffy the Vampire Slayer" during its third season, eventually moving up the ranks as the show's co-producer, and later co-executive producer. Petrie continued to flex his screenwriting talents on the David Boreanaz-starring "Buffy" spinoff "Angel" and former "Buffy" co-star Eliza Dushku's supernatural fantasy series "Tru Calling." In 2005, Petrie returned to the big screen, penning the screenplay for a hit film based on the "Fantastic Four" comic book series.