(written from a Production point of view)
Kevin Peter Hall (9 May 1955 – 10 April 1991; age 35) was the actor who portrayed Leyor in the Star Trek: The Next Generation third season episode "The Price" in 1989. Earlier, Hall had been considered for the roles of two regular The Next Generation characters: Data and Geordi La Forge.  The former role ultimately went to Brent Spiner, while the latter was given to LeVar Burton.
Hall originated from Pittsburgh, Pennsylvania and studied Theatrical Arts at George Washington University, Washington DC. At 7 feet, 2½ inches tall, he was one of the tallest actors ever to perform in any Star Trek movie or television series. His enormous stature landed him numerous roles in films as monsters or aliens, most famously as the Predator in the hit 1987 science fiction action film Predator and its 1990 sequel, Predator 2. He is also remembered for playing Harry the Sasquatch in the 1987 film Harry and the Hendersons (which features art direction by Donald B. Woodruff and set decoration by Linda DeScenna) and in the television series of the same name (starring Bruce Davison).
He made his film debut as a "mutant bear" in the 1979 Paramount Pictures-released sci-fi horror film Prophecy, which starred Robert Foxworth and also featured Graham Jarvis. He later played the hallucinated monster "Gorvil" in the 1982 made-for-TV movie Mazes and Monsters, which co-starred Louise Sorel. In 1984 and 1985, Hall guest-starred on three television series: E/R (with Jason Alexander), Night Court (with James Cromwell and John Larroquette), and the series finale of The Dukes of Hazzard. During the 1985-1986 television season, Hall portrayed Dr. Elvin "El" Lincoln on NBC's superhero fantasy series Misfits of Science.
In the 1986 film Monster in the Closet (in which Hall of course played the monster), Hall worked with Paul Dooley and Henry Gibson. Hall also played the role of Big John in the 1988 film Big Top Pee-Wee; Albert Henderson, Jack Murdock, Jay Robinson, and Kenneth Tobey had roles in this film, as well. In 1989, Hall appeared in the pilot for the short-lived NBC series Shannon's Deal, as did Miguel Ferrer, Spencer Garrett, and Stefan Gierasch. Hall also played the recurring role of Warren Merriwether on the NBC sitcom 227, on which Paul Winfield was a regular.
In 1990, Hall began reprising his role as Harry in the TV series adaptation of Harry and the Hendersons. While working on the series, Hall announced that he had contracted HIV from a contaminated blood transfusion he received prior to the production of Predator 2. He portrayed Harry for the first sixteen episodes of the first season before his illness forced him to give up the role. He died of an AIDS-related illness on 10 April 1991 at the age of 35.