everyone and their dog

A large number of people; most people.

Japanese Meaning

大勢の人々、ほとんどの人々（多くの人が含まれるという意味）

When the new café opened downtown, everyone and their dog seemed to be in line for a latte.

新しいカフェがダウンタウンにオープンしたとき、ラテを求めて大勢の人が列を作っているようだった。

Sense（1）

A large number of people; most people.

Mind you, this was years before everyone and their dog had a cell phone.