speak of the devil

噂をすれば影

Ex

• Speak of the devil, here she comes!
• Speak of the devil! We’re just talking about you.
  ※悪い噂以外でも使える

Reference source

• https://ejje.weblio.jp/content/speak+of+the+devil
• http://girl-lish.com/speak-of-the-devil/