Hound Town (partially lost NBC animated TV show pilot; 1989)
Hound Town was a 1989 animated pilot created for NBC by Prudence Fraser with the intention of catering to a prime-time audience. The pilot was rejected, however.
It was directed by Ralph Bakshi at his Bakshi Animation studio, where he worked with animators from Mighty Mouse: The New Adventures, such as Rich Moore, Andrew Stanton and Jeff Pidgeon. Bakshi claims this to be one of his least favorite works. It has (allegedly) only aired once.
The pilot was available on YouTube at one point, but the channel was suspended before anyone could make a backup of it. This left only a few screenshots until January 17th, 2010, when a copy on MySpleen was uploaded by user "Wrath". This version is in poor quality however, and the first few minutes (including the entire intro) are missing.
But as of June 2017, a clearer copy of Hound Town was uploaded by YouTube user Bsh, including the first part of the pilot, though still missing a minute of the beginning and the entire intro.