Moscow Wolf Boy

This is great. Ivan Mishukov left his Moscow home aged four, and for the next two years ran with a stray dog pack, becoming a classic feral child and, not uncoincidentally, the alpha wolf of the pack. The other dogs fed and warmed him, fighting off police attempts to capture the boy, but eventually the pack was tricked.

This is described in this cool book about feral children, Savage Girls and Wild Boys.