Matthew Patrick/Aliases

MatPat
In school, Matthew's friends called him "MatPat," a combination of the first three letters of his first and last names ("Matthew" and "Patrick" respectively).

Other nicknames and aliases
FatPat: In HOW MANY Calories is Stay Puft Marshmallow Man?, MatPat reveals an alternate personality, one obsessed with sugar and food. FatPat is willing to consume the entire Stay Puft Marshmallow Man, even if it kills him.

Matrick Patthew: A play on the rhyming of "Mat" in Matthew and "Pat" in Patrick, done by switching the second syllables of each name. Stephanie playfully exclaimed this name in Is MatPat ALIVE?! while Matt was explaining how his nickname works in response to the Google search suggestion "matpat's real name".

Game Theory credits

 * Still Mimics the Magus Hand Motions (Is Chrono Trigger's Time Travel Accurate?)
 * Aspires to be Mike Rowe (Super Mario, Pipe Dreams)
 * Apologizes to all Females (Illusion of Gaia, World Wonders)
 * Attached to his vital organs (Mortal Kombat, Fatalities IRL)