Returning from the hunting trip in the woods, the Henderson family's car hits a monster in the street. At first they fear that it was a person, but if they examine the"body" they find it's really a"bigfoot". They believe that it's dead so that they decide to take it home (there could be some money in this). As you imagined, it's not dead. Not even close to being the mad monster that they fear"Harry" to be, so he is an amiable giant.