and his mother

and his mother

A phrase used hyperbolically to express a large number or a majority of people. It usually appears in the construction "everyone/everybody and his mother. I just wanted to have a small dinner party, and now you've invited everyone and his mother! What are we going to feed all these people? I think Shelly is nervous because she gets spooked in big crowds, and everybody and his mother will be at the parade.
See also: and, mother