DETROIT — Alex Karras was a man of many roles.

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’ attorney.

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.