Peter has dirty blonde hair with piercing blue eyes, and pale skin. The front half of his hair is loner than the back, and the bottom of his partially shaved underneath.
Peter has a blue baseball jacket with white sleeves, along withwith a single horizontal red band down the center of the wrist, bottom, and neck cuffs. He wears olive green pants that arolled up to his ankles, and plain, brown shoes. He sometimes uses his jacket as a pouch to put his cats inside. Peter can also sometimes be seen in a backwards red hat.
Peter is generally a witty, kindhearted kid. He seems to like helping out, being the "delivery boy" of the neighborhood. He typically tries to act brave when it comes to something he's scared of doing, and is a sweet boy. When he was first shown, he was laughing at Mary's clumsiness, but tried to help her out a couple times afterwards.
There isn't much to know about him or his family.