The Disney Animation Department in the late 1970s and early 1980s was moribund in the opinion of Brad Bird, and he was quite vocal in his opinion. It ultimately got him fired. He worked on ‘The Plague Dogs’, which was produced in the San Francisco Bay area. ‘The Plague Dogs’ was released in 1982. It is an adaptation of the novel by Richard Adams, who also wrote ‘Watership Down’ from which the animated film was produced in London and released in 1978. Bird was in the Bay area and Jerry Rees joined him after leaving Disney following the completion of ‘Tron’. They worked on developing ‘The Spirit’ as an animated feature film, based on the comics of Will Eisner.
A retirement party was held for John Musker last Sunday (March 18, 2018) – celebrating over 40 years with Disney. 
Musker, along with Bird and Rees, was part of ‘The Rats Nest’ [more on The Rats Nest in a future post] at Disney in the late 1970s and was disenchanted with Disney at that time Bird and Rees were developing ‘The Spirit.’ He, and other friends at Disney, helped Bird and Rees with ‘The Spirit’ in their free time. Musker was very close to deciding to leave Disney and join Bird and Rees, but they weren’t able to get sufficient financial backing for the project to go ahead.