Gregory "Greg" Heffley is the main character of Diary of a Wimpy Kid book series, who is believed to be loosely based on Jeff Kinney. He is very concerned about his popularity level and how he looks in public. He absolutely loves video games, and taking after his older brother Rodrick Heffley. As much as he dislikes his older brother, he takes up a lot of traits from him (selfish, lazy etc.) He also has an interest in cartooning and making comics.
Rodrick Heffley is Greg's older brother. He is the main character (along with Greg) of the second book and a bully throughout the series. He's a junior in high school.
He is always seen with a frown on his face, and one ear, usually on the left side. His eyebrows appear to be thick and bushy, colored only black.
Rowley Jefferson is Greg’s best friend and is a big character in the Diary of a Wimpy Kid series. He has protective parents who aren't caring of Greg's behavior, assuming that he is a bad influence. He is often seen as an anti-hero in the series, despite being the main character’s best friend, as he often does idiotic things to get Greg in trouble