Eurystheus in Heracles (Hercules): The Twelve Labors
Eurystheus is the wimpy king of Argos, who is in charge of assigning all twelve of Heracles' labors. Heracles was actually supposed to be the king of Argos instead of Eurystheus, but Hera interfered and caused Heracles to be born a few hours too late. (More on this story here.) Both Eurystheus and Heracles are great-grandsons of the hero Perseus. Only Heracles really lives up to the name of their great grandfather, though; Eurystheus has a tendency to do wussy things like hide in a big jar whenever Heracles shows up with a scary monster. Oh, Eurystheus.