Sly Eastenegger is a character from The Mask: The Animated Series in the season 2 episode, You Oughta Be in Pictures. He's a world-famous Hollywood action star and film director. His name is a combination of the names of three action movie stars: Sylvester "Sly" Stallone, Clint Eastwood, and Arnold Schwarzenegger.
In You Oughta Be in Pictures, he appears in Edge City to shoot and direct his new action film, The Day After The Day After The Day After, (A parody of the Terminator films and the TV movie, The Day After). What no one knows yet is that Sly and the Director had a stolen U.S. nuclear bomb used as one of the props. This was part of a revenge plot against the critics that made a bad review of his last movie. The Mask kept interfering in Eastenagger's film as he wants to be a star in it, but the Director and Eastenegger refuses due to his wacky and hyperactive nature showing no place in an action film. To get him to leave the film alone, Eastenegger went against the Mask in a Last Action Hero contest with Sly rigging Mask's attempts. When it came to the movie's final scene, Peggy managed to warn Mask and Lt. Kellaway that the bomb is real. Sly returns to stop the bomb, but doesn't know how to and cowardly begs the Mask to disarm it. The Mask manages to disarm the bomb by sitting on it and Sly Eastenegger is arrested by Lt. Kellaway. The former action star was given an atomic wedgie from The Mask when being interviewed by Peggy Brandt before heading to prison.
- Sly Eastenegger shows many references to actors Sylvester Stallone, Clint Eastwood and Arnold Schwarzenegger and their movies. The film Eastenegger was filming in Edge City, named "The Day After. The Day After. The Day After." parodies the Terminator film franchise that stars Schwarzenegger as it includes him being called, "The Ex-terminator" and him saying Schwarzenegger's famous catchphrases from the films, "I'll be back!" and "Hasta la vista, baby!" He does mentions Eastwood's film, A Fistful of Dollars, and does his "Are you feeling lucky, punk?" famous gun-pointing moment from Dirty Harry when pointing his revolver at Stanley Ipkiss during their first encounter. When dealing with The Mask interfering with his film Eastenegger mentions to him, "I'm an action star, alright, not a kindergarten cop." referencing the action-comedy film, Kindergarten Cop starring Schwarzenegger. When cowering in fear when the bomb was about to go off, Eastenegger says, "There ain't gonna be no rematch.", referencing the boxing film, Rocky, starring Stallone.
- The armored suit Eastenegger uses during the firing turret guns challenge against The Mask bares a resemblance to Iron Man from Marvel Comics.
- Eastenegger reveals he wasn't classically trained for acting.