After years of searching, Rex's brother, Titanium Dax, becomes the second Subtopian ever to breach Earth's surface. He and his rock monster slave, Liplor, are thrilled to find Rex alive, but their reunion is soured when Dax threatens to reveal a secret about Rex's origins.
Elenco: Bryan Cranston , Seth Green , Keegan-Michael Key , Jillian Bell , Tucker Gilmore , Zeb Wells , Tom Root , Chris Pine , Heidi Gardner .