Here’s director Terrence Malick in his uncredited role in Badlands–
Story behind the appearance, from this 2009 interview–
Malick also tells us that “Badlands” features his one and only appearance as an actor. “This actor was supposed to show up at 9:30 in the morning for a small scene. We waited, the hours passed, and he didn’t show up. In the end we couldn’t afford to keep waiting, so I put on the cowboy’s hat and performed the part myself.”
“I prefer working behind the camera,” he added with a smile.