Greg Heffley is the protagonist and narrator of Double Down, and the middle child in a family of three boys. Like many pre-teen boys, Greg is not especially interested in school or household chores. Instead, he spends most of his time thinking about how to get famous, how to improve his social standing at school, and how to complete various half-baked schemes that he believes will help him achieve those goals. Also like many young people, Greg is still learning about the world around him. He is aware that some of the things his brother told him when he was younger were lies, but he still has his doubts about others. For example, he refuses to burp when inside because his brother told him that “if [he] burped indoors, the ghost of George Washington would haunt [him]” (123). 

Unlike most book protagonists, Greg is not a dynamic character. He is static, remaining fundamentally the same not just throughout Double Down, but throughout the entire Wimpy Kid series. He sometimes displays brief moments of self-awareness, like when he describes himself as “some ungrateful middle-school kid” (19) that his deceased grandmother would probably not enjoy watching over. Greg’s narration is often ironic, reflecting his somewhat warped idea of himself in a humorous way.