I feel like a lot of 'feral children' characters in fiction would probably fall under therian of some sort. Big example I think of here is San from Princess Mononoke, who was raised by wolves and outright states she's a wolf in one scene. A headcanon that was more popular a few years ago back when How To Train Your Dragon 2 first came out was that Hiccup and his mother were dragonkin. I can definitely see that too, plus it was nice seeing otherkin headcanons without the usual vitriol you get with them (the fandom was pretty chill about it). Several characters in Homestuck could also fall under therian or otherkin of some sort, according to my friend (I haven't read it myself). I feel like Tobias from Animorphs would probably also fall under hawk therian of some sort, despite the ability to shapeshift, but it's been a while since I've read the books. A lot of his thought processes reminded me of therian-related stuff though. A book I read as a child called Panther in Argyll also had a lot of animal person themes in it that I consider pretty crucial in my gradual awakening, looking back on it now. It's about two teenagers who discover they have an ability called the animal spirit that lets them take on the shape of animals, both being melanistic leopards. However, it's considered a very alienating but wild thing and there isn't anything supernatural apart from the theme of shapeshifting itself, since both of them are more ruled by their instincts when transformed (eg. Urges to hunt and do other things humans find unsavoury). These parts especially reminded me of my own mental shifts. They also have to learn how to balance their more wild nature and come to terms with living in a human-dominated world, which really spoke to me, even at that young age.