Marcus is a Retriever like Angela. He has blue eyes like the rest of his siblings and is the second eldest after Sandy. He enjoys cursing because Eva gave him and David permission. His hobbies are watching Pet Park and playing PawStation with his brother. Despite how he acts when the other students are around, whenever Bella is anywhere within earshot, he always refrains from swearing.
He and his siblings eventually got tired of swearing, after they got repeatedly told that their mother should not tolerate swearing, and after getting a paw whack in the face by Queen Ava V. He also realized that it is bad for him to curse.