Mark is Bobby’s closest friend since kindergarten. He is not very popular and used to get bullied by a kid named Andy Mitchell until the sixth book. His room is very messy, and he likes to read books. He once read that eating carrots makes your eyesight better, so he ate them for four months, but all they did was turn his teeth yellow. When he needs privacy, he goes to the boys’ washroom on the third floor, because no one ever goes there. Osa gave him a ring, so he’ll be able to receive Bobby’s journals. He asked Courtney to read it with him, because he knew that she liked Bobby too. Mark is one of Bobby's acolytes. Mark's parents both died, and, in his depression, he joined Saint Dane, who is actually Andy Mitchell! However, his parents are saved because a Saint Dane saves them.