A Ringo is someone in a group of friends who is typically the butt of every joke, the victim of every prank, and generally constantly made fun of, but is always kept in the friend group for these purposes (e.g. the group's punching bag). There is usually only one Ringo per group.
Derived from the popular British band, The Beatles, whose drummer (Ringo Starr) was constantly joked about and pranked by people both within and outside the band. Not to be confused with a group's Yoko Ono.
We always bring our Ringo, Matt, with us on road trips. We shove scrambled eggs in his pants every morning, and he never sees it coming.