In 1990, before Kurt Cobain hit it big with his band, Nirvana, he was a struggling, starving musician. One of his many stabs at fame was penning a theme song for the famous cartoon, Ren and Stimpy. Cobain recorded the song on the cheap, but felt proud of it. Studio executives at Nickelodeon heard the song, thought it was awful, and then threw it out. After Nirvana became famous with their 1991 album, Nevermind, the executives considered this decision to be a mistake.
While it has been confirmed that a couple of copies may still exist, the song has never found its way as a release to the general public. The version Nickelodeon had was trashed, so none of the executives hold a copy. Still, Cobain's estate is yet to comment on the matter. Many Ren and Stimpy fans who are also Nirvana fans are saddened by this.