Rowley Jefferson is the best friend of Greg Heffley, and a major character and deuteragonist, though sometimes antagonist in Greg's perspective, in the Diary of a Wimpy Kid series, often accompanying Greg on his misadventures and getting roped into his schemes, though he plays a more antagonistic role in the books where he and Greg are at odds, such as The Ugly Truth and Hard Luck. In addition, Rowley is the protagonist of Diary of an Awesome Friendly Kid, a spin-off series that involves him and his own tales.
Rowley appears in All Star Smashers as an Assist Character for Greg, appearing in his Side-B, Big Wheel. He also appears in the intro to Greg's moveset, using magic to summon a Smash Ball for Greg to use during his brief battle against Super Minecraft Kid.