The image of Big Chungus comes from a Looney Tunes episode in which Bugs Bunny puffs himself up to mock Elmer Fudd, who had placed a plank of wood and 4 nails over his rabbit hole after saying the now infamous phrase "That'll hold 'im alright". After he leaves that is when Bugs opens the plank walks out and says "That'll hold 'im alright" in a mocking tone.
The image is usually associated with the fake game named Big Chungus on PlayStation 4. The games screenshots on the back of the box promote a single-player adventure mode and a online multiplayer "Battle Royale" mode. Of course these images aren't from a playable build of the game, but instead are doctored screenshots of New Super Mario Bros. U for the adventure mode and Super Smash Bros. Ultimate for the Battle Royale mode. The only difference is that the characters who appear in these screenshots (Mario, Donkey Kong, Link and Inkling) are replaced with Big Chungus.