Accidentally brought to Earth by an experiment conducted by physicist Dr. Walter Jennings, Howard T. Duck hides out with Jennings' young singer Beverly Switzer after saving her from a couple of hooligans. Beverly’s friend and Jennings’ assistant Phil Blumburtt must help Howard and Beverly keep the mad mallard from the authorities long enough to get him home.
The only problem is that another, more hostile alien has hitched a ride on the laser beam that brought Howard to Earth and has taken over Jennings’ body. Now it’s up to Howard, Beverly and Phil to save the planet and prevent the alien from bringing his whole race of Dark Overlords to Earth.