3rd Rock from the Sun 1996

Directed by Robert Berlinger, Terry Hughes | Starring: Joseph Gordon-Levitt, John Lithgow, Wayne Knight, Kristen Johnston

The high commander of an alien expedition lands on Earth -- what he considers to be the least-important planet -- in human form as Dick Solomon. Along for the ride are his alien compatriots Harry, Sally and Tommy -- who is the eldest of the group but is now angrily trapped in a teen's body.