"Quack like a duck" is a phrase that usually means to mimic the sound of a duck. However, there are many synonyms that can be used to express the same idea. Some alternative expressions are "sound like a mallard", "honk like a goose", "twitter like a bird" or "chirp like a cricket". These synonyms can add a bit of variety and humor to one's speech or writing. They can also help avoid repetition or overuse of certain expressions. Regardless of which synonym one chooses, these phrases can add a touch of whimsy and playfulness to any conversation.