- "These clubs were custom made in Japan! The grips are seal skin! I have sensitive palms!"
- ―Mark Fostenburg
Fostenburg is an action movie star who regularly plays loner police officers and a movie director. According to a Vinewood Star Tours guide, in 2007, a fifteen year old Mexican girl was found dead in Fostenburg's pizza oven. The case was closed out of the court and all the charges where dropped. The girl's family now lives next to Mark's mansion in Vinewood Hills.
Events of GTA V
Fostenburg appears in person in the Strangers and Freaks mission Vinewood Souvenirs - Mark, in which protagonist Trevor Philips is tasked with retrieving Fostenburg's unique golf club for Nigel and Mrs. Thornhill. He will be found in Los Santos Golf Club and will be surrounded by three bodyguards. If Trevor gets too close or pulls out a gun, they will shoot him and Mark will try to flee the club.
Although it's possible to get the golf club without killing Mark, one of the gold medal objectives of the mission requires the player to kill Mark with a headshot.
If the player doesn't kill Fostenburg, he will post a Bleet in the Bleeter website after the mission, complaining about the robbery.
He appears to be based on Bruce Willis, although his name is strikingly similar to Mark Zuckerberg's. Similarities to Willis include Fostenburg's starring role in the Die Already film series which in title and subject are reminiscent of Willis' Die Hard films. In terms of appearance, both men have shaved heads.
- He mentions that he has a property in Milan, while playing golf.
- He also says that he has a doppelganger playing golf in Omsk, probably to outwit paparazzi.