Principal Martin Funderburk (Formerly Coach Funderburk) is the Principal of Seaford High. In Return to Spyfall, it's revealed Fubnderburk is actually a spy. He is portrayed by Eric Nenninger.
He first appeared in Kickin' It Old School as the Gym Teacher, trying to hook up with Bethany, only to learn that she has feelings for Rudy. He even called Rudy "Pudy" (only cause the 'R" in his name is missing one of its legs). When he told Rudy that he need to climb the rope to pass, he offered the students a deal; Whoever knocked "Pudy" off the rope doesn't have to do laps for the rest of the year (even Eddie tried to do it so he doesn't do laps) however Rudy passed the test. For the next few episodes he had taken the position of principal and took on a more comedic role and less antagonistic. It is revealed in Return of Spyfall that he is a undercover agent working for the government. He was not in future episodes since his spy headquaters was destroyed.