Greg's 2009 films include featured roles as the beleaguered "Deputy Neale" in Rob Zombie's Halloween II (2009), and a dead-on performance as Andy Warhol in Zack Snyder's spring blockbuster, Watchmen (2009). His recent starring roles include Jeff Broadstreet's Night of the Living Dead 3D (2006), and Sex and Death 101 (2007), alongside Simon Baker. His upcoming films, in 2010, include co-starring roles in The Trouble with Cali (2012), directed by Paul Sorvino as well as Satin (2011) with Melissa Joan Hart and Robert Guillaume.
Greg is often recognized for his co-starring roles in Showgirls (1995) and Starship Troopers (1997). A versatile performer, Greg has also starred in a long list of television shows, such as CSI: Miami (2002), Cold Case (2003), Strong Medicine (2000), JAG (1995) and American Gothic (1995).
As a stand-up comedian, Greg enjoys world-wide fame for his character, "David Sleaze, the Punk Magician". He can be seen on Rodney Dangerfield's "HBO Special". Greg appeared over twenty times on An Evening at the Improv (1982), Saturday Night Live (1975), The Tonight Show Starring Johnny Carson (1962) and many others. Greg has headlined at most of the top comedy clubs in the country and has been the opening act for such entertainment icons as: Cher, Tom Jones and Dolly Parton. His comedic abilities have been described as "absolutely inspired and truly magical" by Duncan Strauss, LA Times.