A genuine triple threat, actor-writer-director Clark Gregg gained respect on the stage and earned credibility in dozens of supporting roles in film and television for two decades prior to becoming part of one of the biggest movie franchises in history. A frequent collaborator with playwright-filmmaker David Mamet, Gregg's early film appearances included such Mamet efforts as "Things Change" (1988) and "The Spanish Prisoner" (1997). He later garnered substantial praise for his turn as a pre-operative transsexual opposite Adrian Grenier in "The Adventures of Sebastian Cole" (1998). Gregg made his debut as a feature-film screenwriter with the paranormal mystery "What Lies Beneath" (2000), turned in more respectable supporting work in films like "One Hour Photo" (2002) and appeared with regularity on such hit shows as "The West Wing" (NBC, 1999-2006). After writing and directing an adaptation of Chuck Palahniuk's novel "Choke" (2008), Gregg made his first appearance as secret agent Phil Coulson in the superhero spectacular, "Iron Man" (2008). More Coulson cameos followed, eventually leading to an expanded role in the summer blockbuster "The Avengers" (2012), which teamed a number of Marvel Comics' most iconic heroes on screen for the first time. While not boasting the marquee recognition enjoyed by many of his costars, Gregg remained one of the more versatile and employable talents in Hollywood.