何なに者ものか

noun

someone; somebody

Used when the identity of a person is unknown or deliberately unspecified, often with a nuance of mystery or suspicion.

• 何なに者ものかが窓まどから侵しん入にゅうしたようだ。

  It seems someone broke in through the window.

• 彼かれは何なに者ものかに尾び行こうされていた。

  He was being followed by someone.