Benjamin "Benjy" Heffley is Greg's cousin. He wears a diaper and has three strands of hair like Greg and Manny. He seems to be around 2 or 3 years old, but is mentioned to be reading books at the age of 1, and next year reading chapter-books without being potty-trained, which his parentsbrag about. According to Greg, at one time he could only say "no" and "shut up" but he also can say "Hey! Poopy diaper here!" Also,
according to his parents, he can also fully read, which Greg highly doubts. He also appears in the Do-It-Yourself Book in a question where he says "A little help?" He was the reader at Uncle Gary's wedding.
- Diary of a Wimpy Kid: The Ugly Truth
- Diary of a Wimpy Kid Do-It-Yourself Book (also in extended version)