Although not much is told about Kevin's appearance, he is known to be quite short, but is much taller in the fifth book. He wears glasses, too.
Kevin is only a supporting character, making few appearances each book. He is often made fun of because of his height, even though he is only small because he skipped several grades. Even the book club doesn't like him so much. He shows to like Jess a lot, and won't take a hint that she doesn't like him back.