Tinker Bell (partially found first draft of animated film; 2007)
Tinker Bell is a 2008 movie starring the titular fairy from Disney's Peter Pan movies and their then-recently-launched Disney Fairies book series, and this movie itself also spawned no less than 5 sequels. While the completed movie was about Tinker Bell arriving in Pixie Hollow and the immediate time afterward, the original version that was under production was much different in its plot.
One particular draft, which received a trailer and various tie-in stories on the Disney Fairies website, was about human children that believed in fairies being brought to Pixie Hollow, where they would attend fairy school. Attending fairy school was mandatory for fairies, as a fairy had to complete fairy school in order to be allowed to use pixie dust.
There were some Flash games on an older version (ca. 2006-2011, when it comes to the American version) of the official Disney Fairies websites that elaborated further on the draft's plot, including one Flash game that served as a tour of Pixie Hollow, but the Flash games are also lost. Another flash game, that served as a "Which fairy talent do you have?" questionnaire, placed Fairy Mary in the role of a class teacher at the school (In the released movie she had instead become the leader of the pots-and-pans talent group), which indicates that she could've had such a role in the first draft.
The Pixie Dust Tree also had a visibly different design, being purple instead of green. An earlier version of the trailer mentioned that the movie would not only be released on DVD, but also on VHS, which would have made for a very late release for a video format that by then had been phased out by most movie publishers.
However, as part of John Lasseter's decision to greatly reduce or alter Disney's direct-to-video output, as he had just become Chief Creative Director of Walt Disney Animation Studios, he is reported to have thought of a work-in-progress screening of the draft as being virtually unwatchable and demanded that the plot be heavily rewritten. Another potential factor was the budget had by then already reached $30 million, which was a lofty sum for a direct-to-video feature in the mid-2000's. The completed movie's release would later add yet more to the budget, resulting in a total cost of $50 million.
The song in the trailer, To The Fairies They Draw Near by Loreena McKennitt, was eventually used in the completed movie, but now with a different context, as it was played when Tinker Bell was born through a laugh and was flying through London as a non-sentient flower seed. However, no other animated content from the original draft is currently known to have been reused or to have resurfaced.