The line comes from The Ren and Stimpy Show, the Nickelodeon cartoon that premiered in 1991 and built its humour around Ren Hoek, a short tempered chihuahua, and his cheerful cat friend Stimpy. Their arguments were a running part of the series, with Ren often blaming Stimpy for every disaster. Clips and quotes from the show later spread through forums, video edits and soundboards, where this accusation survived on its own. Its lasting appeal is the contrast between Stimpy's usual innocence and Ren's explosive, completely disproportionate anger.