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 movies, 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,this made Ruby the first girl to be suspended in Greg's school.