Beth is a refrigerator located in the commissary on the Galaxy One.
Gary named her during his prison sentence because he got lonely, and treats her like an intelligent being (or at the very least a robot), despite her being just an ordinary fridge. KVN and the S.A.M.E.S. also think of her as a robot; in Chapter 5, while the others were away on a mission, KVN was seen making out with Beth and drinking champagne with her, which envied three of the S.A.M.E.S. who proceeded to fight over her affections.
She survived the destruction of the Galaxy One in "Chapter 10". At the start of "The Toro Regatta", she is picked up by Clarence's ship along with Gary's body, and deemed valuable enough to keep.