What do Americans mean by an 800-pound gorilla?

800 Jin gorilla is a person or thing that needs no scruples because it is powerful.

This idiom comes from a riddle. Q: Where can an 800-pound gorilla sleep? A: I can sleep wherever I want. It can be seen that this slang is often used to describe a person or an organization that is very powerful and needs no scruples.

It means that now China is strong and begins to challenge the existing rules.