The line comes from The Simpsons, the long-running animated series that first aired in 1989, where Charles Montgomery Burns is the miserly owner of Springfield's nuclear power plant. His drawn-out 'Excellent' became one of the show's most recognisable catchphrases, usually delivered while he plots or celebrates a scheme going his way. Clips of the moment spread through early soundboards, reaction videos, and later short-form video, where it works as shorthand for villainous approval. Its simplicity keeps it instantly recognisable decades later.