Bambi's Children

Bambi's Children was a planned sequel to the 1942 animated Disney film Bambi and based on the book of the same name.

Plot
The film would have dealt with Bambi's adult life and his relationship with his newfound family shortly after he becomes the new Great Prince of the Forest.

Why It Was Cancelled
The most likely reason would be because Bambi did not perform very well due to being released during World War II. This ultimately cost its box office returns. Another reason could be because Walt Disney himself did not believe in producing sequels (though he was willing to make exceptions with some of his live-action films, like Old Yeller).

Result
While the film was never made, Dell Comics published a Walt Disney Productions comics adaptation in 1943.

In 2006, a direct-to-video sequel, Bambi II, was released; however, this film serves as a midquel rather than a direct followup, as it chronicles Bambi's childhood and relationship with his father, the Great Prince of the Forest, who takes him in shortly after his mother is killed by hunters. Brian Pemental, who directed the midquel, intended to direct a third film focusing on Bambi's adulthood, but this was shelved when John Lasseter put an end to the company's direct-to-video sequel business.