I really likes stags as forest-kings. I like the idea of sacred forest grooves, where an ageless, intelligent stag keeps the peace by killing any predator larger than a fox.
That's not what they do in real life of course. In real life they fight over pussy, and get their horns tangled together, and die. Stag horns don't exist to repel predators, they exist to reduce the deer population before winter hits, but the imagery is still good.