Gallie
A Gallie is a nickname for Gallagher, and it's the best nickname ever. It's like the name of the person who makes everything happen.
Gallie: 'I'm Gallagher, and I'm the best at it.'
Gallie: 'I'm the name, and I'm the best.'
Gallie: 'I'm Gallagher, and I'm not even slightly humble.'