David Paymer (born August 30, 1954) is an American actor and television director.
 He has been in films such as "Mr. Saturday Night", "Quiz Show", "Searching for Bobby Fischer", "City Slickers", "Crazy People", "State and Main", "Payback", "Get Shorty", "Carpool", "The American President", "Ocean's Thirteen", and "Drag Me to Hell".
 Paymer was nominated for an Academy Award for Best Supporting Actor in 1992 for "Mr. Saturday Night."
 He played the lead role as the Boss in "Bartleby", an adaptation of Herman Melville's "Bartleby, the Scrivener."
 He played a mob boss in the television series "Line of Fire".
Ennis del Mar (Del Mar in the film) is the fictional main character of the short story "Brokeback Mountain" by Annie Proulx and the 2005 Academy Award-winning film adaptation of the same name directed by Ang Lee.
 Ennis's story is depicted by his complex sexual and romantic relationship with Jack Twist in the American West, over two decades from 1963 to 1983.
 In the film, he is portrayed by Heath Ledger, who was nominated for the Academy Award for Best Actor for his performance.
Jack Palance ( ; born Volodymyr Palahniuk (Ukrainian: Володимир Палагню́к ); February 18, 1919 – November 10, 2006) was an American actor and singer.
 He was nominated for three Academy Awards, all for Best Actor in a Supporting Role, winning an Oscar in 1992 for his role in "City Slickers".
Joshua "Josh" Mostel (born December 21, 1946) is an American actor.
 The son of Zero Mostel, he is best known for his supporting roles in films such as "Jesus Christ Superstar" (1973), "Harry and Tonto" (1974), "Sophie's Choice" (1982), "City Slickers" (1991), "Billy Madison" (1995), and "Big Daddy" (1999).
William Edward Crystal (born March 14, 1948) is an American actor, writer, producer, director, comedian and television host.
 He gained prominence in the 1970s for playing Jodie Dallas on the ABC sitcom "Soap" and became a Hollywood film star during the late 1980s and 1990s, appearing in the critical and box office successes "When Harry Met Sally..." (1989), "City Slickers" (1991), and "Analyze This" (1999) and providing the voice of Mike Wazowski in the "Monsters, Inc." franchise.
Jacob Benjamin Gyllenhaal ( ; born December 19, 1980) is an American actor.
 A member of the Gyllenhaal family and the son of director Stephen Gyllenhaal and screenwriter Naomi Foner, Gyllenhaal began acting as a child with a screen debut in "City Slickers" (1991), followed by roles in "A Dangerous Woman" (1993) and "Homegrown" (1998).
 His breakthrough performance was as Homer Hickam in "October Sky" (1999) and he garnered an Independent Spirit Award nomination for Best Male Lead for playing the title character in the indie cult hit "Donnie Darko" (2001), in which he played a psychologically troubled teenager alongside his older sister, Maggie Gyllenhaal.
 He subsequently appeared in another indie film, "The Good Girl" (2002) and the climate fiction-disaster film "The Day After Tomorrow" (2004), portraying a student caught in a cataclysmic climate event.
The Oklahoma City Slickers was the name given to two different American soccer clubs based in Oklahoma City.
 The first team competed in the second American Soccer League in 1982 and 1983, and as the Oklahoma City Stampede in the United Soccer League in 1984 and 1985.
 The second Oklahoma City Slickers competed in the USISL from 1993 to 1996.
Jake Gyllenhaal is an American actor who has appeared in over 35 motion pictures (including some yet to be released), three television programs, one commercial, and four music videos.
 He made his film debut in 1991 with a minor role in the comedy-drama "City Slickers".
 In 1993, he appeared in "A Dangerous Woman", a motion picture adaptation directed by Gyllenhaal's father Stephen Gyllenhaal and co-written by his mother Naomi Foner that was based on the novel of the same name by Mary McGarry Morris.
 In the following year, he portrayed Robin Williams' son in an episode of the police procedural television series ""; the episode was directed by his father.
 In 1999, Gyllenhaal starred in the Joe Johnston-directed drama "October Sky"; the film was received warmly by critics, and Gyllenhaal's portrayal of the NASA engineer Homer Hickam was praised.
Jack Twist is a fictional character of the short story "Brokeback Mountain" by Annie Proulx and the 2005 Academy Award-winning film adaptation of the same name directed by Ang Lee, where he is portrayed by American actor Jake Gyllenhaal.
 Jack's story is depicted by the complex, sexual, and romantic relationship he has with Ennis Del Mar in the American West from 1963 to 1983.
City Slickers II: The Legend of Curly's Gold is a 1994 American Western comedy film directed by Paul Weiland.
 It is the sequel to "City Slickers" (1991) and stars Billy Crystal, Jack Palance, Jon Lovitz, and Daniel Stern.
 Although a mild financial success, the film did not reach the popularity of the first, receiving a generally negative response (a 19% approval rating on Rotten Tomatoes).
 It was nominated for a Razzie Award for Worst Remake or Sequel.

Question: Jack Twist was a character portrayed by which American actor who debuted in City Slickers?
Answer: Jacob Benjamin Gyllenhaal