Cast[]
- Kevin as Greg Heffley
- Stuary as Rowley Heffley
- Gru as Roderick Heffley
- Mark as Susan Heffley
- Bob as Manny Heffley
- Jorge as Holly Hills
- Tim as Mr. Jefferson
- Margo (from Despicable Me) as Mrs. Jefferson
- Pipsqueak (from Dr. Seuss' The Lorax) as Sweetie
- Young Once-ler (from Dr. Seuss' The Lorax) as Chirag Gupta
- Scarlett as Patty Farrel
- Agnes (from Despicable Me) as Heather Hills
- Herb as Mr. Gerabit
- Jerry as Grandpa
- The Lorax (from Dr. Seuss' The Lorax) as The Craium Shaker Guy