Is it a worm or a dragon? The next sentence can be said: it is an eagle, not a dog. The idiom "a worm is a dragon" comes from the ancient literati's classification and evaluation of things, and is usually used to describe the pros and cons of things. The next sentence can be said: "It's an eagle or a dog", which means that both the eagle and the dog have their own unique abilities and characteristics, so we can't simply judge them by their quality. "Is it a worm, a dragon, an eagle or a dog" expresses an understanding of the diversity and complexity of things, and also reminds people to be comprehensive and objective when evaluating things.