Title "What's Eating Robert" is a spoof of the popular movie "What's Eating Gilbert Grape". Struggling to come up with a suitable title, director Chris Mallery and editor Marion Sistena were goofing off in English class bouncing movie title spoofs off one another. Finally Chris came up with "What's Eating Robert". Another possible spoofed suggestion was "There's Something About Robert"(There's Something About Mary) which was thought of by Marion.
The Dean of Grant High, "Mac", was the first choice to play the police officer/school administrator that arrests the disgruntled student. He was too busy to be part of the project but he did supply the prop handcuffs used in the video which he confiscated from a student.
At the end of the video Robert throws the gun, placed inside a brown paper bag, into the nearby L.A. River. Inside the paper bag are actually old scrap wood blocks. They did many takes of this shot so at the end of filming several bags with wood blocks were thrown into the river.
While filming, one scene the camera was left running too long and captured the actors pretend to beat up Robert (Griffin). An insert shot was needed to bridge two shots that could not be edited together properly so the accidental footage of the actors pretending to beat up Robert was used as a flashback/dream sequence.
Most of the shots featured a simple realistic looking plastic toy gun. For one of the close-up shots, they used a real air pellet gun.