Master Splinter's from Nickelodeon's Teenage Mutant Ninja Turtles and this screenshot's taken from Valve's Garry's Mod. It is re-enactment of Paramount's Charlotte's Web's Templeton Weight Gain scene and a gift for  CBFox.

Splinter was going around to test out many, many carnival food and loved them so much that he would buy more, enough to stuff his face extremely and transform his belly into a mountain, in a way. He now then begin dancing around and proudly show it off for anyone to behold.