Mr. Underwood

Mr. Underwood is Greg's Physical Education teacher. He has a very little role in the first book, but it's bigger in the film. His role in The Last Straw was a minor but important appearance, where he was walking with Mrs. Mancy to mark the students' dancing abilities as 20% of their P.E. grades. In Cabin Fever, he was also shown during a push-up test. In the movie, he is replaced by Coach Malone.In The Third Wheel it was shown Ruby Bird  bit him on his arm and Ruby's teeth got stuck on his arm.