Star Phantom was one of four Phantoms of Ancient Babylonian summoned by Prime Evil in an elaborate ceremony that included him cooking a pot with various ingredients, including one teaspoon of salamander scales, one cup of bats toenails, one large dash of dragon powder and a liquid from an ancient Babylonian flask. Finally the pot began to glow and the four giant urns in which the remains of the Ancient Babylonian Phantoms were held began to crack, revealing the four ancient 'professionals'.
Prime Evil needed the combined energy to bring the section of the universe in which the Earth rotated, to a complete stop. Then he would force the Time Gyroscope to move in reverse, making the time on Earth reverse.
Despite their great and ancient powers, the four Phantoms of Ancient Babylon were easilly defeated when they came face to face with the Ghostbusters and their Ghost Dematerializers.
The Star Phantom makes his only appearance in the episode The Bad Old Days.