Pip: That’s the wolf’s true form? He looks…

Seras: …ripped?

Pip: Harsh, mignonette! I was going to say like a child who’d had a good dream, but that too.

Seras: He wasn’t a child.

He’s an adult who couldn’t handle the responsibility. Same as everyone else in Millennium. Being human is hard, so they gave it up. Some were just more literal about it than others.