- Age: 25
- Height: 6'2"
- Weight: 187 lbs
- Hair Color: Brown
- Eye Color: Brown
- Mother: Sylvia Traian Walker
- Father: Al Walker
- Siblings: Joey Walker, Paul Walker, Ashley Walker
- Marital Status: Divorced
- Children: Samuel Walker (age 4)
- Birthday: December 29th
- Talents: Speed and strategy
- Weaknesses: Tall, willowy blonds
- Hobbies: Martial arts, playing the piano
- Dislikes: Sweets, having nothing to do
- Beliefs: Believes in himself, mainly
- Ambitions: To command his own unit one day
- Quirks: He can only grin on one side of his face; as an Iotian, he often mimics people without realizing it, which sometimes causes offense.
Born on Oxmyx (known in the Federation as Sigma Iotia II), Matty had a strict upbringing as the oldest of four siblings. His father believed heavily in the truth, a belief he instilled in all his children. Because of this, Matty became an excellent liar, spinning many falsehoods but paying the price when he was caught. Still, he set an excellent example for his two younger brothers and younger sister, attending a boy's military academy on Oxmyx and applying for the Starfleet Marines directly after graduation. He received a scholarship and studied strategy under von Clausewitz and P'Tren.
During training, Matty met and fell in love with Alyssa Stronge, a fellow Marine. Since fraternization was not allowed, the two kept their relationship a secret until Alyssa discovered she was pregnant. Matty did the proper thing and proposed, and they were quietly married. Alyssa gave birth to a healthy baby boy, who they named Samuel, after Alyssa's grandfather. However, the marital bliss did not last long, and Alyssa requested a divorce soon after Matty's graduation from the Marines (Alyssa had to drop out of the program due to her pregnancy). Unable to reconcile their differences, Matty agreed. He requested partial custody of his son, but due to the dangerous nature of his job, it was refused. He visits Sam when he can on leave, though he and Alyssa still have a strained relationship.
- 238105.10 - Graduated middle of his class
- 238105.12 - Stationed aboard the USS Astraea
- 238312.03 - Stationed aboard Starbase 36
- 238406.21 - Assigned to Ambassador Odon
- 238501.08 - Stationed aboard Starbase 60
- 238509.26 - Stationed aboard USS Challenger