4. Monsters Inc.(2001)
Monsters Inc. is very important to the overall theory without having much to do with the actual war and apocalypse. The film breaks the chain of events taking place in the current time and presents the viewer with an alternate dimension where monsters exist and can go back and forth from our dimension to theirs through doors. This is going to be important once the animal/human/toy war breaks out because it is never clarified if the monsters take part but it can be assumed that they do since they have no way to sustain their livelihood without scaring the children of Earth.