William "Bill" Walter is featured mostly in Diary of a Wimpy Kid: Rodrick Rules and was a member in Loded Diper as the lead guitarist. He was played by Fran Kranz in the movie.
Bill Walter is a 35-year-old high-school dropout who does not have a job, and still lives with his parents. In the second book, it revealed that the reason Rodrick invited Bill into his band was because he was voted "Most Likely to Be a Rock Star" when he was in high school. If Frank sees Bill, it puts him in a bad mood for the rest of the day, which was claimed by Greg in Rodrick Rules. This is because he is a reminder of his greatest fear of Bill being Rodrick's role model. The fear includes Rodrick copying Bill; becoming a no job slacker just like Bill. In the talent show, he flicks his tongue up and down like a rock star, Susan says "I don't like that!". It was mentioned in the fourth book how Rodrick met Bill; The two met when Rodrick was camping out for the night with his friends to get concert tickets. When Rodrick was eating a bag of potato crisp chips, Bill asked if he could have some of his chips.
In the movie, he is like a loser. He is the main antagonist of the movie. His character is notably different. He joins the band and invites himself to a dinner at the Heffleys' house. He tells Rodrick and Greg that being a major rock star is a little tough, but then tells them that the life of a rock star is awesome by making note of the female fans and parties. When Rodrick is grounded from playing at the talent show, Rodrick says that he just got Bill in, and Frank Heffley says "That doesn't really improve your case. Bill is kind of a jerk." This proved to be true when Bill replaced Rodrick with another drummer and planned to perform without him, despite Rodrick being the one that started the band. During a guitar solo, Rodrick kicks Bill out of the band.
In the first movie he had a cameo in the credits.
- In the online version, Bill drives the Löded Diper van, rather than Rodrick, who owns an El Camino style pickup truck.
- He does not appear in Diary of a Wimpy Kid (film), but seen in a cameo at the end credits.
- Bill is included in the 2nd movie, (Rodrick Rules), and plays lead guitar in Rodrick's band, Loded Diper.