How to create a mysql user that can access from any host but localhost

I was asked to create a mysql user that can connect to the server from any host but localhost. I tend to believe that "%" also means localhost but according to my teacher, localhost is not part of "%" and that CREATE USER user@"%"; should do the job but my tests proof otherwise. The only solution that I've found to solve the problem is with CREATE USER user@localhost ACCOUNT LOCK; Can anybody educate me about this?