Louis the Bear

Louis the Bear was a planned Disney film that was going to be made sometime in the late-1960s and 1970s.

Plot
A bear called Prima escapes zoo assisted by some mice.

Why It Was Cancelled

 * 1) Walt Disney died before prouction could begin.
 * 2) Louis Prima was diagnosed with a brain tumor.

Result

 * The film was permanenly cancelled.
 * The concept for the film was later used in the 1977 film The Rescuers.