He once chaperoned on Nate's Timber Scouts camping trip, but ended up ruining the experience for everyone after being sprayed by a skunk because he scared it. According to Nate, everyone smelled of skunk for a whole day.
He attended P.S. 38 as an adolescent, and he was the inventor and first hero of the "Mud Bowl", despite being not being very good with schoolwork. He made friends with Simon and Gayle when they played at the "Mud Bowl" on the same team.
- Marty thought Nate and Gina are in a relationship with each other after catching them holding hands in Big Nate Strikes Again, much to their horror and dismay.
- He was in P.S. 38 and was the hero of the first "Mud Bowl".
- He is heavier than Nate and Ellen combined together.