JonTron left Game Grumps in 2013 to focus on his own content and projects. He wanted to pursue his YouTube channel, JonTronShow, which allowed him to create videos that aligned more closely with his personal style and interests. The decision was amicable, and both he and his co-host, Arin Hanson, have expressed support for each other's endeavors since the split.
Game Grumps - 2012 Super Mario Bros- 2 Nintendo'd - PART 2 - Game was released on: USA: 2013
Game Grumps - 2012 Mister Mosquito Suck the Blood - Part 1 was released on: USA: 13 May 2013
Game Grumps - 2012 Stretch Panic A Bit of a Stretch - Part 2 was released on: USA: 31 May 2013
JonTron - 2010 Top 10 Necessary Video Game Sequels 3-9 was released on: USA: 17 May 2012
Game Grumps - 2012 Animal Crossing Wii Joining a Gang - Part 2 was released on: USA: 1 September 2012
At this time it does not seem likely that JohnTron will return to Game Grumps. After a successful stint on Game Grumps, he left in June of 2013 to pursue other endeavors which include producing content for his own channel.
Jon Jafari has: Played Head of Sonic Team in "JonTron" in 2010. Played JonTron in "JonTron" in 2010. Played Malkovich in "JonTron" in 2010. Played Sniperwheel in "TOME: Terrain of Magical Expertise" in 2011. Played himself in "Game Grumps" in 2012.
Game Grumps - 2012 Guest Grumps Grant Kirkhope was released on: USA: 2013
Game Grumps - 2012 Game Grumps Childs Play Charity Special 6-9 was released on: USA: 2013
Game Grumps - 2012 Battletoads was released on: USA: 11 October 2012
Game Grumps - 2012 A Bug's Life was released on: USA: 21 June 2013
Game Grumps - 2012 Mike Tyson's Punch-Out Around the World was released on: USA: 2013
Game Grumps - 2012 Mega Man 7 This Game Rocks 1-3 was released on: USA: 18 July 2012
Game Grumps - 2012 Yoshi's Island The Best Game Ever - Part 1 was released on: USA: 18 September 2013
Game Grumps - 2012 Super Mario Bros- 2 Nintendo'd - PART 2 - Game was released on: USA: 2013
Game Grumps - 2012 Chulip Looking for Leo - Part 8 was released on: USA: 27 May 2013
Game Grumps - 2012 Chulip Pay Your Workers - Part 4 was released on: USA: 3 May 2013