James Hellwig on April 7, performing for the audience during WWE Monday Night Raw in New Orleans. He died the next day at 54. (David Grunfeld/AP)

In the annals of World Wrestling Entertainment grapplers, James Hellwig and his 20-inch-thick calves did not cut the most imposing figure. The late Andre the Giant towered over Mr. Hellwig, universally known as the Ultimate Warrior.

He did not display in the ring the technical wizardry of Shawn Michaels and Bret Hart, nor did he convey the Hollywood charisma of showmen such as Hulk Hogan and the Rock.

Yet, for a period in the late 1980s and early 1990s, Mr. Hellwig, who died at 54 on April 8, days after induction into the WWE Hall of Fame, brought a certain Rambo-like intensity to the spectacle of professional wrestling.

There was his long, flowing hair, his steroid-fueled physique, his jungle face paint, his signature galloping entrance, and his guttural, nearly incoherent taunts at nemeses in the ring or the steel cage.

A onetime aspiring chiropractor, Mr. Hellwig hailed from Indiana and transformed himself into a man of mystery hailing from “parts unknown.” He legally changed his name to Warrior after a financial dispute with the WWE.

Sports journalist and wrestling authority Mike Mooneyham called Mr. Hellwig “one of the biggest fan favorites in the history of modern wrestling. He was chiseled like granite in the early days of the ‘Big Man’ in wrestling, during the steroid era.”

Mooneyham said that, along with Hogan and the late Randy “Macho Man” Savage, Mr. Hellwig and his broad appeal helped make possible the national expansion of the World Wrestling Federation, as it was then called.

During his WWF career, Mr. Hellwig was a designated “good guy” who played out “feuds” with opponents such as “Ravishing” Rick Rude, who once choked him with a steel bar, and Mark “The Undertaker” Calaway, who once locked the Ultimate Warrior in a coffin.

Mr. Hellwig became such a commercial draw that WWF impresario Vince McMahon crowned him the successor to longtime champion Hogan. The transition came in 1990, during an event dubbed WrestleMania VI before a crowd of more than 60,000 fans in Toronto. Mr. Hellwig defeated Hogan with a move called the “gorilla press.”

Mr. Hellwig’s reign was short-lived. He clashed with McMahon over money and merchandising rights. His use of bodybuilding drugs also became problematic at a time when the federal government was cracking down on the distribution of anabolic steroids.

In their 2002 book about the WWF, “Sex, Lies and Headlocks,” journalists Mooneyham and Shaun Assael wrote that “behind his back the Boys called him Anabolic Warrior for all the steroids it took to gain him his superhuman frame.”

After leaving the WWF in 1992, Mr. Hellwig wrestled periodically and started a short-lived wrestling school in Scottsdale, Ariz., called Warrior University. He had a supporting role in the 1993 action film “Firepower.” He largely retired from the ring in 1998 and became a motivational speaker and conservative activist.

“Ultimate Warrior ran because I was running him,” he wrote on his Web site. “He was intense because I already was. Whatever I am doing — wrestling, writing, working out, speaking, even weaving pot holders — I am going to do it with action and intensity.”

James Brian Hellwig was born June 16, 1959, in Crawfordsville, Ind., and began bodybuilding at 11 because, “like everybody else, I was just the small, insecure kid who wasn’t into any sports.”

While studying for a career as a chiropractor, he won the Mr. Georgia title in 1984 from the National Physique Committee, the country’s premier amateur bodybuilding organization. The next year, he dove fully into professional wrestling.

Chiropractic work bored him, he once told interviewer J.M. Manion, but “the smell of the gym and the sound of the weights and just sweating, that’s what I love.”

He appeared as the Dingo Warrior for the Texas-based World Class Championship Wrestling before jumping in 1987 to the WWF, where he was rechristened the Ultimate Warrior.

His first marriage, to Shari Lynn Tyree, ended in divorce. Survivors include his wife, the former Dana Viale, and their two children, Indiana Warrior and Mattigan Warrior.

Mr. Hellwig’s relationship with the wresting world was frequently litigious. In recent years, he sued unsuccessfully over a WWE video release called “The Self-Destruction­ of the Ultimate Warrior.”

But his legacy was inextricably linked to the wrestling organization and its boom years. He was inducted April 5 into the WWE’s hall of fame and two days later appeared on the wrestling TV show “Monday Night Raw.”

The next day, Mr. Hellwig collapsed while walking with his wife in Scottsdale and was pronounced dead at a hospital. A Maricopa County spokeswoman said the medical examiner’s office will conduct an autopsy.

On “Monday Night Raw,” he delivered to his fans a message that in retrospect seems an eerie premonition of his death:

“No WWE talent becomes a legend on their own. Every man’s heart one day beats its final beat. His lungs breathe their final breath. And if what that man did in his life makes the blood pulse through the body of others and makes them believe deeper in something larger than life, then his essence, his spirit, will be immortalized.”

“You, you, you, you, you, you are the legend makers of Ultimate Warrior.”