He's not very bright, but he's super atheletic and friendly.
He went to Gallagher High School, and excelled in swimming.
When Alex was chased into the pool, Matt got Alex out, and found The Dolly in the bottom of the pool. Once Alex stopped screaming, Matt felt sorry for Alex and decided to help him since he was being stalked.
Matt started staying at Alex's house, along with Christopher Robin III, and acted as a body gaurd.