He’s given birth to a name, and even something non-existent can become something if he says so. His power doesn’t lie in his claws and teeth, but in the lies he can turn into truth by making others believe in them.
It’s one thing to win by being bigger and stronger, but to win without anyone else even catching on until much later? That’s true power, and turning nothing into something comes easily to his tongue.
In the end, though, he finds he needs someone to believe in him so he can exist, so he looks for someone who doesn’t know him, and steals everything that can’t be stolen.