Rowley Jefferson

Rowley is Greg's best friend by far. Even though that Greg has done some bad things to Rowley, like breaking his hand and big toe, and getting him in trouble for something he didn't do, they still remain friends. In the first book, Rowley ate the cheese, but no one knew. Besides that, Rowley is often nice to everyone and he always has his mouth open. Rowley has very little will power, since Greg can convince him to do almost anything that he tells him to do. Rowley never has appeared with his mouth closed, leaving him with an open happy face, or sad happy face.

Rowley is very immature, as heavily implied in Diary of a Wimpy Kid: Rodrick Rules. There, he gets a whole bunch of kiddie toys and a girlish diary - however, he's happy about it. This shows that Rowley is immature. Also, in Diary of a Wimpy Kid: Dog Days, he ends up taking the chocolate-covered raisins over a trip to the grand championship of Twisted Wizard 2.