FernGully: The Last Rainforest(1992)
A curious fairy named Crysta comes upon a rain forest near Mount Warning, Australia. Despite her beliefs that humans live on Mount Warning, the forest spirit tells her that humans have long since gone extinct, driven away by Hexxus, the spirit of all that is evil and toxic to nature. After a few forest friends come across a dead part of the forest, they fear Hexxus is awakening. Crysta then shrinks a human male named Zak after falsely assuming he is helping destroy the forest. Zak then tells her the truth about what is going on and must work with Crysta and the forest animals to stop the destruction of the forest and stop Hexxus from awakening.
This is a vintage TV spot for the movie.