Giant butt-eating Morty lived alongside his grandfather Giant butt-eating Rick in a dimension populated with giants. They created a small city which they could destroy. Rick Sanchez and Morty Smith from Dimension C-132 visited them without knowing the scale to this dimension, and was attacked by their alternate selves.
Giant butt-eating Morty was not seen after the fight, leaving his fate unknown. His grandfather Rick was still looking for the intruders afterwards.