The fantastic duo

Having the body of Officer Knight and the head of Greg the Dog, his personality is Greg's. Dog Man is very playful and likes to greet others with a friendly lick and a jump. But when trouble arises, he behaves seriously, just like Officer Knight. He always gets the job done, no matter what. He's also very cheerful and happy when nothing bad is happening in town. He's affectionate and attentive to everyone, especially Little Petey, whom he adopted. He also takes care of Petey, especially when he's not being sly and mean. But when necessary, he's serious, especially about things like his house.

Petey is known for his wit and fiery temper. He has a way with words that allows him to get what he wants, a tactic he used to manipulate others and enact his evil schemes in earlier books as the villain. However, one of his main weaknesses is becoming easily irritated by seemingly minor inconveniences and the immature or careless behavior of others. His anger issues cause him moderate levels of stress. Despite his impatience, he has occasionally shown empathy towards others, even in the early books.

When Petey unexpectedly became the father of his kind-hearted son, Li'l Petey, his behavior subtly began to change. He became more thoughtful and reluctant to continue with his evil schemes, and he grew to love Li'l Petey dearly, despite having always tried to make him a fellow villain before Lord of the Fleas. Li'l Petey inspired him to finally become a good person, and he has been ever since Brawl of the Wild.