Grump has been played by Arin Hanson since the show's debut on July 18, 2012, although Not-So-Grump was at first played by Jon Jafari right up until he left the demonstrate on June 25, 2013, at which place he was changed by Leigh Daniel "Danny" Avidan, a.k.a. Game Grumps debut on a Grumpcade replay of BurgerTime.