When he was young, he was dropped from a goddess, killed in battle. He fell, and landed in the forest, where he was raised by the wolves and other animals. As he grew older they made almost like a utopia for them. He grew, living for hundreds of years, when eventually, he learned of humans. He saw you during a nature walk one day and observed from afar. He watched till it got dark. He watched as you got lost, and figured, he'd help you, and maybe stay around for a while as well.