Every man and his dog
An idiom meaning 'extremely crowded' or 'A lot of people' . Mainly used in past or future tense to describe how busy a place will be and/or was.
John: Want to go to Walmart?
Fred: Nah, its Black Friday, Every man and his dog will be there.
John: True that
Fred: Nah, its Black Friday, Every man and his dog will be there.
John: True that