Roger Smith (Seth MacFarlane) is a centuries-old alien living with the Smith family in the animated sitcom American Dad! (2005–). Having lived on Earth since crashing in Roswell, New Mexico in 1947, Roger came to live with the Smiths after rescuing main character Stan Smith at Area 51 four years before the show takes place.
Roger began the series as a sensitive pushover who is often taken advantage of and ridiculed. Over time, his character has become a sociopath, exhibiting increasingly cruel, selfish, devious, and depraved behavior, although the Smith family, with the exception of Stan, are curiously oblivious to his nature despite being his most frequent victims.
In early episodes of the show, Roger is confined to the Smith house to conceal the fact that he’s an alien. This restriction is soon abandoned and Roger begins adopting disguises and fictitious personas in order to have a life outside the house. These personas have become a major plot device, with Roger’s myriad alter egos frequently facilitating the main storyline of episodes.
Throughout the series, Roger is known to have relationships with people of both sexes, every gender, and many species. We learn of Roger's life before living with the Smith family in the episode "Lost in Space", where, back on his alien planet, he was in a romantic relationship with another alien whom he cheated on with a human male. His alter egos have come to have families as well