The Ren & Stimpy Show (non-existent unused Kurt Cobain song for Nickelodeon animated series; 1990)
In 1990, before Kurt Cobain hit it big with his band, Nirvana, he was a struggling, starving musician. It is rumored that one of his many stabs at fame was pinning a theme song for the famous cartoon, Ren and Stimpy.
During an interview with Nerdist Podcast, voice actor Billy West claimed that one day Cobain visited the Spümcø Animation headquarters and stated that he wanted to write a song for the series, executives didn't like Kurt's song, and then threw it out.
No copies of the alleged song have resurfaced, and as such the song's existence has not been confirmed. Even if copies of the song still exist (assuming it even did in the first place), it is said that the version Nickelodeon had was trashed, making it unlikely that any of the executives hold a copy. Cobain's estate has not commented on the matter.