Walter (Killer) Kowalski, one of professional wrestling’s biggest stars and most hated villains when wrestlers offered a nightly menu of mayhem in the early years of television, died Saturday in Everett, Mass. He was 81.

Kowalski’s death was announced by his wife, Theresa, who said he had been hospitalized since a heart attack in early August.

At 6 feet 7 inches and 275 pounds or so, Kowalski was a formidable figure who delighted in applying his claw hold, a thumb squeeze to an opponent’s solar plexus, when he was not leaping from the top strand of the ropes and descending on his foe’s chest.

Emerging as a featured performer in the early 1950s, he became a TV celebrity with wrestlers like Antonino Rocca, Lou Thesz, Gorgeous George, Haystacks Calhoun and Nature Boy Buddy Rogers.