Robotnik and his Gameboy
Robotnik and his Gameboy is a flash poop created by CraaazyCat13 and uploaded on February 6, 2008. It is by far his most popular video, and inspired an actual game based off the game seen in the poop.
The poop depicts Grounder giving Dr. Robotnik a Nintendo Game Boy, with a game called "Super Robotnik Land", which stars Robotnik himself. Gameplay shown consists of simple platforming sequences involving coin collecting, Sonic as an enemy, who must be defeated using the Pingas, and a boss battle against "Kingman".
While the original video description held a disclaimer stating that Super Robotnik Land was not a real game, a user named DezzanRobotnikLand created a real version of it. Download links are included in the video below.