pip squeak

/ˈpɪp skwiːk/
noun
  1. A small or unimportant person, especially a child, often used in a playful or mildly insulting way.
    • Don't worry about that pip-squeak — he can't hurt you.
    • The big kid called the little one a pip-squeak and laughed.
    • Even as a pip-squeak, she was the best player on the team.
Antonyms
What does "pip squeak" mean? | whatsthatwordmean | whatsthatwordmean