Dumbo II (partially found production material from cancelled Disney animated sequel film; 2000s)
From The Lost Media Wiki
Dumbo II was a planned sequel movie to the 1941 animated Disney film Dumbo that would have been directed by Robert C. Ramirez, who also directed Dreamworks's Joseph: King of Dreams. It was scheduled to be released in 2001, but production was cancelled by John Lasseter after he was named Chief Creative Officer of Walt Disney Animation Studios in early 2006.
Plot
Taking place specifically one day after the events of the first film, the story would have involved Dumbo, Timothy Q. Mouse and a host of other baby animals, each of whom represented a different stage of childhood, getting separated from the circus. While trying to find their way back, each character learned how to fix their flaws.