Teenagers who run away from home to live in the wilderness may become feral. As they become more and more feral, they gain some supernatural powers (a la Peter Pan - ability to fly, things they imagine come true - possibly quite powerful), but at the expense of their humanity and ability to speak, comprehend complex subjects, etc. Maybe they have a leader: the most feral of them all.
A regression into a fantasy childlike state.
There are crimes for which a man is not killed, but chased into the wilds, away from his home and country, to not return or be killed on the spot. In one culture is the condemned mutilated, and even his vocal cords are damaged so that the voice is unrecognizable to his friends and family. This is the punishment for people too obsessed with their own prestige.