Few students mess with the master at the Killer Kowalski Institute for Professional Wrestlers. That's understandable. He's got 30 years of experience and 280 pounds of menacing gristle. But occasionally a brash pupil needs a lesson, and Kowalski slips into the ring to show, not tell. Within seconds his challenger finds himself slammed against the ropes, seized by a wrist and a leg on the rebound and spun about on Kowalski's broad shoulders. "There always comes a point when the student thinks he's better than the teacher," says the onetime World Wide Wrestling Federation superstar. "I show 'em who's boss."

Those moments aside, Kowalski, 49, rarely lives up to his fearsome professional nickname. A longtime vegetarian, he lives sedately in Reading, Mass., speaks to youth groups whenever he can, and presides over his school for grapplers in the drafty YMCA in nearby Salem. Yet even now hardly anyone calls him by his given name, Walter—not since a night in Montreal 28 years ago. Kowalski was wrestling Yukon Eric and had his adversary tangled in the ropes. Suddenly he leaped in the air, and as he came down sliced off Eric's cauliflower ear with his shinbone. Shocked, the bloodied Eric began shrieking "My ear! My ear!" while the furious crowd bellowed "Killer!"

From that moment on Kowalski was cast as a villain, dressing in purple and courting the wrath of the fans. A looming 6'7" target, he was more than once forced to defend himself from angry spectators outside the ring. "But," he says, "I really try to avoid confrontations. It isn't so hard. I don't go to bars, and my size keeps most guys from trying anything. As long as they leave me alone and don't touch me, I can walk away. But if someone lays a hand on me, I go mad."

The son of Polish immigrants, Kowalski was an all-around schoolboy athlete. Like his father, he labored in an auto plant near the family home in Windsor, Ont. After hours he worked out in a YMCA, where a gym instructor taught him some holds. A few local bouts later, an out-of-town promoter made him an offer. When Kowalski couldn't get time off for a match in St. Louis, he quit the assembly line and turned pro. It was the era of Gorgeous George and Nature Boy Buddy Rogers. Kowalski beat both of them and countless others, but not without paying for it physically. To this day he cannot tilt his head back or fully extend his arms without wincing. Still, he will not see a doctor or visit a hospital. "Once I had a bad cut over my left eye," he remembers, "and someone talked me into going to an emergency room. I had to wait and wait, even though I was bleeding all over the place. Finally the doctor came in. He asked me for my autograph. I walked out, put an herb medicine on the cut, and eventually the infection disappeared. No stitches. Nothing."

Retired from the ring since 1977, Kowalski concedes that most wrestling on TV is entertainment rather than sport, but claims that matches on the professional wrestling circuit are "for real. That's where people get hurt." Though his students are keen on practicing scowls, he drills them instead in ring safety and self-defense, demonstrating a repertoire of 75 holds, while offering counseling in nutrition and body building. Four two-hour sessions a week for a month cost $300, and an extended course of four months or more, $1,000. Since he began teaching classes a year and a half ago, Kowalski boasts that 12 of the 14 pupils he has "graduated" are performing as pros. They appear in preliminary matches on the circuit.

One of them is a chunky waitress named Venetia Guerrasio, who is molding herself in the Killer's image. "It's been an advantage to work out with guys," she maintains. "They're taller, bulkier. It makes me feel special." And, oh yes, her ring name is Vicious Venetia Rude. "Yeah, a villain," she said with a grin. "I respect them more."