Sean Gunn has joined the cast of “Guardians of the Galaxy” director James Gunn’s new horror film, “The Belko Experiment.”

James Gunn made the announcement Thursday on his Facebook page. He’s also revealed castings last week of “Scrubs” alum John C. McGinley, “Fruitvale Station’s” Melonie Diaz, “The Newsroom” star John Gallagher Jr. and “Scandal” president Tony Goldwyn.

“You may recognize him from one of my other films — Kraglin in ‘Guardians of the Galaxy,’ Alien Orphan in ‘The Specials’ (film), Toby in ‘SUPER,’ Humanzee in ‘Humanzee,’ or numerous characters in our James Gunn’s PG Porn series (which Sean co-created with me and our brother Brian),” James Gunn said.

“Even more of you might recognize him as Kirk from ‘Gilmore Girls. ‘In addition to being my brother, he’s also my favorite actor in the world to work with so I’m excited to welcome him aboard ‘Belko’ as Marty Espenscheid, a stoner cafeteria worker who has his own ideas about who is behind Belko.”

The director also revealed the casting of Steve Agee for “Belko.”

“In the film Marty’s best friend is Chet Valincourt, played by one of my best friends, Steve Agee. Steve of course had an iconic role in ‘SUPER’ as ‘sleepy comic book guy who calls a child an asshole.’ But he’s also one of the best standup comics around, and is known for his regular roles on ‘The Sarah Silverman Program’ and his recurring role on ‘New Girl.'”

The story, directed by Greg McLean from Gunn’s script, follows an American company after it’s mysteriously sealed off in South America. Employees show their true colors when they are ordered to kill each other or risk being killed themselves.

Gunn, who is producing with Peter Safran, is also on board to direct and produce Marvel-Disney’s “Guardians of the Galaxy 2,” which will hit theaters on May 5, 2017.