Future Mordecai and Future Rigby

They are Mordecai and Rigby's future counterparts that were introduced in "Mordecai and the Rigbys". In the future, they are successful musicians and had everything they ever wanted, where Future Rigby had a tattoo of a shark on his armpit and it was implied Future Mordecai scored with Future Margaret. They also pretended they had British accents (even though the present Mordecai and Rigby's voices were American), and rarely took off their sunglasses, as "their future was so bright". They were summoned to the present by Mordecai and Rigby when Mordecai spilled a can of soda on some record players that somehow sent the future selves to the present. They taught Mordecai and Rigby everything on how to be musicians except for the part on how to play the guitar. On open-mic night, they were miracously wonderful, singing the song Party Tonight, until Mordecai dropped his guitar pick and discovered that the guitar music and the lyrics he was singing were coming from a radio. Mordecai and Rigby refused to let that happen, and their future selves began to disappear, revealing that the only reason they were successful was because of their lip-syncing. Mordecai and Rigby officially broke up the band, sending the future selves back to their time, or even killing them. It is implied that another pair of future duplicates were created by the future they chose.

Trivia
Shown when Future Mordecai sings on a track so Mordecai and Rigby can lip-synch, Future Mordecai can sing with a non-British accent.