everybody and his mother

Phrase

idiomatic

(idiomatic) A large assortment of people.

Japanese Meaning

大勢の人々、非常に多くの人たち / あらゆる種類の人々、誰もが含まれる集団

When she announced the free concert, everybody and his mother showed up in the park.

彼女が無料コンサートを発表すると、公園にはありとあらゆる人が集まった。

Sense（1）

(idiomatic) A large assortment of people.