Question: Which voice actor plays the voice of the cartoon character that is most famous for his semi-intelligible speech and his mischievous and temperamental personality?

Context:
John Kassir
John Kassir (born October 24, 1957) is an American actor, voice actor and comedian.
 He is known as the voice of the Crypt Keeper in HBO's "Tales from the Crypt" franchise.
 Kassir is also known for his role as Ralph in the Off-Broadway show "Reefer Madness", as well as its film adaptation, as well as his voice over work as Buster Bunny (taking over for Charlie Adler late in the final season of "Tiny Toon Adventures"), Ray "Raymundo" Rocket on "Rocket Power", the mischievous raccoon Meeko in "Pocahontas" and its direct-to-video sequel, Jibolba in the "Tak and the Power of Juju" video game series, and the current voices of Pete Puma in "The Looney Tunes Show", and Deadpool in "" and the "" series.
 He has also recently done the voice of Rizzo for the newest Spyro game, , and voiced Ghost Roaster in "", as well as Short Cut in "" and Pit Boss in "".
 He is also known for his various roles in season 1 of "The Amanda Show".
 He voiced the Ice King in the Adventure Time (pilot) but was replaced by Tom Kenny for the series.
 He also provided additional voice over work for "Sonic the Hedgehog", "Eek!
 The Cat", "The Brothers Flub", "Dead Rising", "Casper's Scare School", "Spider-Man 3", "", "Diablo III", "Monsters University", "The Prophet", "" and "The Secret Life of Pets".
Jim Backus
James Gilmore Backus (February 25, 1913 – July 3, 1989) was an American radio, television, film, and voice actor.
 Among his most famous roles were the voice of nearsighted cartoon character Mr. Magoo, the rich Hubert Updike III on the radio version of "The Alan Young Show", Joan Davis' character's husband (a domestic court judge) on TV's "I Married Joan", James Dean's character's father in "Rebel Without a Cause", and Thurston Howell III, on the 1960s sitcom "Gilligan's Island".
 He also starred in his own show of one season, "The Jim Backus Show", also known as "Hot Off the Wire".
Clarence Nash
Clarence Charles "Ducky" Nash (December 7, 1904 – February 20, 1985) was an American voice actor.
 He is best known for the Disney cartoon character Donald Duck, whose distinctive voice he provided for 50 years, also known as the voice of Daisy Duck in 1940.
 He was born in the rural community of Watonga, Oklahoma, and a street in that town is named in his honor.
 In 1993, he was posthumously made a Disney Legend for his contributions to Walt Disney films.
Arthur Q. Bryan
Arthur Quirk Bryan (May 8, 1899 – November 18, 1959) was an American actor, voice actor, comedian and radio personality, remembered best for his longtime recurring role as well-spoken, wisecracking Dr. Gamble on the radio comedy "Fibber McGee and Molly" and for creating the voice of the Warner Brothers cartoon character Elmer Fudd.
Donald Duck
Donald Duck is a cartoon character created in 1934 at Walt Disney Productions.
 Donald is an anthropomorphic white duck with a yellow-orange bill, legs, and feet.
 He typically wears a sailor shirt and cap with a bow tie.
 Donald is most famous for his semi-intelligible speech and his mischievous and temperamental personality.
 Along with his friend Mickey Mouse, Donald is one of the most popular Disney characters and was included in TV Guide's list of the 50 greatest cartoon characters of all time in 2002.
 He has appeared in more films than any other Disney character, and is the most published comic book character in the world outside of the superhero genre.
List of fictional actors
Fictional stories sometimes feature a fictional movie or play.
 In these cases, occasionally, a fictional actor appears.
 In movies, it is not infrequent that a real, famous actor plays the role of a fictional person who is also an actor.
Johan Hedenberg
Johan Hedenberg (born 9 October 1954) is a Swedish actor and voice actor.
 Prior to becoming an actor he worked as a Prison Officer at Svartsjö Anstalten (Blacklake penitentiary).
 As a child, he was beaten by his father until his late teens, when he physically assaulted him.
 After the attack, Hedenberg's father never touched him again but their relationship became very frosty.
 In the 1980s, he spent much time in the company of Thorsten Flinck and Paolo Roberto.
 In 1984, after getting into a fight, he lost his job at Dramaten.
 He soon found work in various TV-series and at the end of the 80's found work in the emerging business of voice acting.
 With the introduction of commercial television in Sweden, animated shows on TV became more common and Hedenberg found steady work as a voice actor which he still benefits from.
 As a voice actor, Johan Hedenberg became a popular choice to cast as villains because of his deep voice.
 He has provided the Swedish voice for several famous cartoon villains such as Dr. Julian Robotnik, Prolix, The Shredder, Dr. Drakken and Dick Dastardly.
 In 2012, Hedenberg miracoulosly survived an operation to remove a tumor from his heart which was at high risk at spreading.
 Hedenberg says that the incident gave him new perspectives on life.
 He has two daughters from a previous marriage.
Jimmy Weldon
Jimmy Weldon (born September 23, 1923) is an American voice actor, ventriloquist, and former television host.
 He is best known as the voice of the Hanna-Barbera cartoon character Yakky Doodle the little Duck and the host and ventriloquist in the locally produced television series "The Webster Webfoot Show."
Donald Duck talk
Donald Duck voice, formally called buccal speech, is an alaryngeal form of vocalization which uses the inner cheek to produce sound rather than the larynx.
 The speech is most closely associated with the Disney cartoon character Donald Duck whose voice was created and performed by voice actor Clarence Nash, and by Tony Anselmo after Nash's death in 1985.
Blaine County, Oklahoma
Blaine County is a county located in the U.S. state of Oklahoma.
 As of the 2010 census, the population was 9,785.
 Its county seat is Watonga.
 Blaine County is the birthplace of voice actor Clarence Nash, the voice of Disney's Donald Duck.

Answer: Clarence Nash