Buttworld is an alternate dimension that first appeared in the episode "Close Rick-Counters of the Rick Kind" when Rick and Morty were running away from the Council of Ricks. Buttworld is, as its name would imply, butt themed and everything in it is derived of things related to butts, farts, toilets etc.
Buttworld is a dimension where everything is made out of butts, or toilet related things. It has large, hairy white butts that serve as mountains that protrude from the ground, which appears to be liquid fecal matter and urine. On closer inspection, however, the ground is completely solid. The butt mountains periodically release green fart clouds into the air, which later create larger fart clouds. There are also two kinds of tree-like growths visible, one being bare wooden rods, with toilet rolls hanging on perpendicular "branches", and the other, giant toilet plungers. Much else remains unknown.
It appeared in the episode "Get Schwifty", where Morty was using the Portal gun to find Dimension C-137, but kept coming across other, different dimensions, one of which was Buttworld. When Morty arrived here, he stated, "Oh, shit!"
- Buttworld may be a reference to the music video for Sir Mix-a-Lot's "Baby Got Back," which features many giant butts.