In "Morty's Mind Blowers", Rick and Morty might have left this dimension when Morty intercepted a highly sensitive conversation between three Squirrels, which eventually lead to a squirrel apocalypse.
Being too lazy to change things back to normal, Rick traveled to an alternate dimension where his counterpart had been lucky with the situation (and did fix it) and was also conveniently killed by a failed experiment alongside Morty. When they arrived, they took the dead bodies of that dimension's versions of themselves, buried them in the backyard, and continued in this timeline.
In "Morty's Mind Blowers", a forgotten memory that Morty had revealed that Dimension C-131 was corrupted, when Morty found out that all the squirrels in this dimension ran an underground conspiracy and those squirrels found out he knew too much and started chasing after him. When Rick found out about this, he told Morty they may have to abandon Dimension C-131 and relocate to a new dimension. It is unknown exactly when this event transpired and if the two actually did abandon Dimension C-131 or managed to solve the problem.
- "Rick Potion #9"
- "Raising Gazorpazorp"
- "Rixty Minutes"
- "Something Ricked This Way Comes"
- "Close Rick-Counters of the Rick Kind"
- "Ricksy Business"
- "A Rickle in Time"
- "Auto Erotic Assimilation"
- "Total Rickall"
- "Get Schwifty"
- "Big Trouble In Little Sanchez"
- "Interdimensional Cable 2: Tempting Fate" (Cameo)
- "Look Who's Purging Now"
- "The Wedding Squanchers"
- "The Rickshank Rickdemption"
- "Rickmancing The Stone"
- "Pickle Rick"
- "The Whirly Dirly Conspiracy"
- "Rest and Ricklaxation"
- "Tales From the Citadel" (Cameo; in the pre-intro and post-credits scenes)
- "Morty's Mind Blowers" (last confirmed appearance)
- "The ABC's of Beth" (possibly)
- "The Rickchurian Mortydate" (possibly)
- "Edge of Tomorty: Rick Die Rickpeat" (possibly)
- "The Old Man and the Seat" (possibly)
- "One Crew Over the Crewcoo's Morty" (possibly)
- "Claw and Hoarder: Special Ricktim's Morty" (possibly)
- "Rattlestar Ricklactica" (possibly)
- "Never Ricking Morty" (possibly; cameo)
- "Promortyus" (possibly)
- "The Vat of Acid Episode" (possibly)
- "Childrick of Mort" (possibly)
- "Star Mort Rickturn of the Jerri" (possibly)
- "Mort Dinner Rick Andre" (possibly)
- "Mortyplicity" (possibly)
- "A Rickconvenient Mort" (possibly)
- "Rickdependence Spray" (possibly)
- "Amortycan Grickfitti" (possibly)
- "Rick & Morty's Thanksploitation Spectacular" (possibly)
- "Gotron Jerrysis Rickvangelion" (possibly)
- "Rickternal Friendshine of the Spotless Mort" (possibly)
- "Forgetting Sarick Mortshall" (possibly)
- "Rickmurai Jack" (possibly)
- According to the songs in Apple Music, it appears that this dimension´s designation is C-131.