What is a synonym for "squeaky wheel"?

A synonym for squeaky wheel, especially in the idiom the squeaky wheel gets the grease, is the complainer, the whiner, the loudest voice, the person who makes a fuss, or the troublemaker who gets attention. The idiom means the person who complains most gets help or attention, so synonyms for squeaky wheel in figurative sense include squeaky person, complainer, squealer, whiner, nag, or attention-seeker. Literally, squeaky wheel means a wheel that squeaks and needs oil, so synonyms literally are creaky wheel, squeaking wheel, noisy wheel, or whining wheel. In business context, squeaky wheel could be called the vocal customer, the demanding client, or the persistent complainer. If you want another idiom with similar meaning, the loudest duck gets shot is opposite, but the wheel that squeaks the loudest is greased first is same. So best synonyms are complainer, whiner, or the one who makes noise to get attention. For example, instead of saying he is the squeaky wheel, you could say he is the complainer who always gets attention or he is the vocal one who gets fixed first. The phrase itself is idiomatic, so there is no single perfect one-word synonym.