While on the run from the Catholic Church and Bill Donohue, Stan and Kyle, along with the bunny Snowball, visit Professor Teabag, an expert on the history of Easter. Professor Teabag tells them he is busy at the moment, but when Stan mentions the Hare Club for Men, he welcomes them in to tell them the story. Professor Teabag shows them a picture of the Last Supper. He brings their attention to something that looks like an egg, lying in front of St. Peter, the first pope. He then tells them that St. Peter was no man, but a rabbit. To this, Kyle responds, "Peter Rabbit?"
He goes on more to say the Church would not let Leonardo da Vinci paint St. Peter as a Rabbit, so he was forced to paint him as a man. He did though leave clues as to the true identity of St. Peter, such as the egg. With laser technology, they were able to look past the second layer of paint, to the original depiction of St. Peter as a Rabbit. When Stan question why Jesus would want a rabbit to run his church, Professor Teabag tells him Jesus knew no one man could speak for everyone in a religion. Men are intolerant and corrupted, but Rabbit's are pure. The Catholic church covered it up though, and put a man in charge. The Hare Club for Men has been painting Easter Eggs ever since to keep the truth alive.
He saved the boys at a price of his own life when ninjas stormed his manor and killed his Butler. He put a box of Peeps in his microwave and they expand rapidly filling the whole manor, killing the Professor and the Ninjas.
He wore black glasses, a green jacket with a blue waistcoat and a yellow checkered shirt underneath. He wore dark green trousers and always had a walking stick with him.
- The professor's name, Teabag, is a possible innuendo, referencing the sexual act, teabagging.