The Simpsons S13 E18 I Am Furious (Yellow)

"Just a product of society that's lost its good manners."

Inspired by a cartoonist who speaks at the school as part of a career day assembly, Bart creates a comic book series based on Homer and his anger problems, which turns into a popular Internet cartoon series called Angry Dad. Homer finds out about this and is at first outraged, but after talking to his family, he decides to try to become a less angry person.