The cover has three little animals in a flying contraption.
In the movie a gas truck or something similar crashes and begins polluting all the little animal holes, and a few little animals are sent to save the others or something. I remember a part where they are trying to cross a field at night, but there's an owl in a tree and they can't get across. There's also a part where they join birds I think? I think its made by the people who made the Secret of Nimh.