3rd Rock from the Sun - Season 6 - Eps 18: Mary Loves Scoochie (2)
With the identity of Scoochie revealed to be Liam Neesam, who had visited Pendelton three years ago, Dick is panicked, and follows Liam and Mary to dinner, where he overhears Liam offering her a job with a six-figure salary. The other Solomons suggest that Dick reveal himself as another alien in order to gain Liam's respect. When he does, however, Liam reveals that he doesn't care for Mary, but that she is part of a huge plan to transform the Earth's entire population into monkeys, and rename it Planet Monkey World, so that it may be an exhibit for aliens. Meanwhile, Sally, Harry and Tommy discover that their favorite movie, Arthur 2: On the Rocks' has a 'prequel' - Arthur.
About 3rd Rock from the Sun

Title: 3rd Rock from the Sun
First Air Date: 1996-01-09
Last Air Date: 2001-05-22
Status: Ended
Rating: 7.5/10 (from 503 votes)
Language: EN
Seasons: 6
Total Episodes: 139
Network: NBC
Genres: Family, Sci-Fi & Fantasy, Comedy, Drama
Production Companies: Carsey-Werner Company
Synopsis
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.
Cast

John Lithgow
Dick Solomon

Kristen Johnston
Sally Solomon

Jane Curtin
Mary Albright

Joseph Gordon-Levitt
Tommy Solomon

Elmarie Wendel
Mamie Dubcek

French Stewart
Harry Solomon

Simbi Khali
Nina Campbell

Wayne Knight
Don Orville