If you're looking for anime similar to Unico: Kuroi Kumo to Shiroi Hane, you might like these titles.
Unico the unicorn is once again in a new place. During his journey with the West Wind, Unico meets Tsubasa, a talking tree boy. The Earth has become totally ruined to the extent that no creature can live there, because humans have drained it of all resources and destroyed the environment. Unico and Tsubasa go on a journey to find a way to make the Earth habitable again. They finally meet the Sphinx and the "time fairy" (Astro Boy/Atom) at the end of their hard journey. They decide to go back to the past and prevent humans from taking the wrong path.
When a tree close to a river gets destroyed by a human construction site, a family of rats is forced to move out and find a new home before the winter comes. On this unforgettable journey, they'll run into many dangerous situations while also meeting valuable allies along the way.
Peter the Root Fairy and the animals of Placid Forest attempt to force humans out of their forest to keep them from cutting down the trees. At first they stage a peaceful protest, but the humans do not listen. With no other choice, the animals carry out an operation to hinder and annoy the humans.
What do a giant panda, a red panda and an opossum have in common? Besides the fact that they all travel around on the same flying pink dragon, they also are part of a team entrusted with protecting the environment. Together, the trio helps save fellow animals in distress, keeps species from becoming extinct, and make sure the world’s destructive foes get what they deserve. Fur farmers, woodcutters and poachers beware! These animals are on a mission to keep Earth safe by whatever means necessary!