Fearsome NFL defensive lineman. Lovable TV dad. Hilarious big-screen cowboy.
And in the end, a dementia victim who blamed the NFL for his illness along with thousands of former players in lawsuits accusing the league of not doing enough to protect them from the long-term effects of head injuries.
The 77-year-old Karras, who managed to be tough, touching and tragic in the span of a lifetime, died Wednesday at his Los Angeles home surrounded by family members, said Craig Mitnick, Karras' lawyer.
Karras was one of the NFL's most ferocious — and best — defensive tackles for the Detroit Lions from 1958-70, bulling past offensive lineman and hounding quarterbacks.
The charismatic bruiser went into acting after his football career, and in his signature scene dropped a horse with a punch as the soft-hearted outlaw Mongo in the 1974 comedy "Blazing Saddles." He also portrayed the father in the 1980s sitcom "Webster," along with his actress-wife Susan Clark, and was in the "Monday Night Football" broadcast booth along the way.
"Perhaps no player in Lions history attained as much success and notoriety for what he did after his playing days as did Alex," Lions president Tom Lewand said.
Born in Gary, Ind., Karras starred for four years at Iowa and was later inducted into the College Football Hall of Fame. Detroit drafted him with the 10th overall pick in 1958, and he was a three-time All-Pro defensive tackle over 12 seasons with the franchise.
He was the heart of the Lions' defensive front that terrorized quarterbacks. The Lions handed the champion Green Bay Packers their only defeat in 1962, a 26-14 upset on Thanksgiving during which they harassed quarterback Bart Starr constantly.
Packers guard Jerry Kramer wrote in his diary of the 1967 season about his trepidation over having to face Karras.
"I'm thinking about him every minute," Kramer wrote.
Karras was All-Pro in 1960, 1961 and 1965, and he made the Pro Bowl four times. He was recognized by the Pro Football Hall of Fame as a defensive tackle on the All-Decade Team of the 1960s and retired from the NFL in 1970 at age 35.
But Karras also had run-ins with the NFL long before his lawsuit. He missed the 1963 season when he was suspended by NFL Commissioner Pete Rozelle in a gambling probe. Karras insisted he only wagered cigarettes or cigars with close friends.
"Alex Karras was an outstanding player during a time when the NFL emerged as America's favourite sport," the league said in a statement. "He will always be remembered as one of the most colorful characters in NFL history."
For all his prowess as a player, Karras may have gained more fame as an actor.
He had already become known through George Plimpton's behind-the-scenes book "Paper Lion: Confessions of a Last-String Quarterback," about what it was like to be an NFL player in Detroit.
Karras and Plimpton remained friends for life, and one of Karras' sons is named after the author. Karras played himself alongside Alan Alda in the successful movie adaptation of the book, and that opened doors for Karras to be an analyst with Howard Cosell and Frank Gifford on "Monday Night Football."
In Mel Brooks' "Blazing Saddles," Karras played a not-so-bright, rough-around-the-edges outlaw who not only slugged a horse but also delivered the classic line: "Mongo only pawn in game of life."
In the 1980s, he played a sheriff in the comedy "Porky's" and became a hit on TV as Emmanuel Lewis' adoptive father, George Papadapolis, in the sitcom "Webster."
"I had a very heavy heart this morning and I did not know why. I understand now," Lewis said. "Rest in peace, my friend."
Karras also had roles in "Against All Odds" and "Victor/Victoria." He portrayed the husband of famed female athlete "Babe" Didrikson Zaharias in the TV movie that starred Clark in the title role. The two later formed their own production company.
Clark has said that Karras started to show signs of dementia more than a dozen years ago, and she said his quality of life had deteriorated because of head injuries sustained during his playing career. He could no longer drive and couldn't remember recipes for some of the favourite Italian and Greek dishes he used to cook, she said.
In April, he became the lead plaintiff in a suit filed in U.S. District Court in Philadelphia. He is among about 3,500 retired football players who accuse the league of not protecting them better from head injuries.
"This physical beating that he took as a football player has impacted his life, and therefore it has impacted his family life," Clark told the AP earlier this year. "He is interested in making the game of football safer and hoping that other families of retired players will have a healthier and happier retirement."
The NFL maintains that it did not intentionally seek to mislead players and says it has taken action to better protect players and advance the science of concussion management and treatment.
"It's an ironic tragedy that Alex had to live with devastating effects from playing the game he loved," Mitnick said.
He said the NFL on Aug. 30 filed a motion to dismiss all the players' actions, and the plaintiffs' response is due Oct. 30.
Mitnick said the family hasn't decided whether to donate Karras' brain for study, as other families have done. The family released a statement listing his other ailments as kidney failure, which recently hospitalized him, stomach cancer and heart disease.
Karras later wrote an autobiography, "Even Big Guys Cry," and two other books, "Alex Karras' and "Tuesday Night Football."
In addition to Clark, his wife of 37 years, he is survived by their daughter and his four children from his first marriage to the late Joan Powell.
AP Sports Columnist Tim Dahlberg, AP Pro Football Writer Howard Fendrich and AP Television Writer Frazier Moore contributed to this report.