I just finished watching Zootopia 2 and it was pretty good. I think I know what the third movie is about. Since we've had a villain be a large animal and a medium animal already, I think the villain will be rodent(s) of some kind. Because of the after credits scene, and my conclusion with the type of villain, I think that the birds will be upset because of the rodent(s) buncha' tubes that they travel through are in the sky so that makes it hard to fly. Idk though, just my hunch.