The Story of Nidalee
Nidalee has lived in the Kumungu jungle longer than she can clearly remember, raised by a family of cougars after she was separated from or abandoned by the human settlement she was born in. The jungle made her: she learned to hunt by watching cougars hunt, learned to move by moving the way cougars move, and eventually stopped distinguishing between human and cougar as categories that applied to her. She is both. She shifts between forms without thinking about it.
The jungle she protects is ancient and densely magical — the Kumungu is one of Runeterra's most intensely alive places, a tangle of competing predators and prey that has reached its own equilibrium over millennia. Nidalee maintains that equilibrium not from any ideological commitment to nature but from the instinct of a predator who knows her territory and what threatens it. The things that threaten it are increasingly human.
She has had encounters with the outside world — with explorers, with hunters, with people who come to the Kumungu looking for what's inside it and discover that the jungle has its own opinions about visitors. She is not hostile to humans specifically. She is hostile to the things humans do when they enter her jungle with intentions rather than respect. The distinction, from the outside, can look very similar.