Dennis Franks, 68, an exuberant former special teams captain for the Eagles, longtime businessman, motivational speaker, musician, and author, died Saturday, Oct. 16, of cardiac arrest at his home in Cornelius, N.C.

A fiery, aggressive football player during his four seasons in the NFL, the 6-foot-1, 241-pound offensive lineman was the epitome of the Eagles from 1976-78. Playing under equally fiery coach Dick Vermeil, Mr. Franks, like those Eagles teams, was super scrappy.

Loquacious, intelligent, optimistic, and eager to lead, the undersized Mr. Franks reacted to his role as a backup center on the Eagles by punishing opponents — and often gloating about it — on punts and kickoffs, and challenging his teammates, even star linebacker Bill Bergey, to match his reckless abandon.

He described his play to the Daily News in 1978 as “an M-80 right before it blows off, and you’re inside the casing waiting for the ref’s whistle. Every step gets bigger and bigger as you’re running down the field until you hit somebody, and you just explode.”

He was indeed brash, violent, and played rough-and-tumble in 44 games over three seasons for the Eagles. He started one game in 1977, and was chief rabble-rouser and special teams captain in 1978. He reported to training camp that year before he was required.

“Denny Franks is one of those guys who eats up this kind of physical torture, coming back for more and more with a deranged grin on his face,” wrote Gary Smith of the Daily News in July 1978.

Mr. Franks played in 13 games for the Detroit Lions in 1979, as their special teams captain, after being cut by Vermeil.

Reporters and fans loved him in Philadelphia. He was accessible, jovial, and handed out colorful quotes like Halloween candy. “Special teams is an attitude play,” he told the Daily News in 1978. “Who wants to throw themselves at somebody going 40 mph? You need crazy people and maniacs. It’s hit or be hit. You can’t worry about your body. He who hesitates gets killed.”

After retiring from the game in 1980, the season the Eagles finally played in the Super Bowl, Mr. Franks kicked off his career as a businessman, motivational speaker, and assistant high school football coach.

Since 1993, he had been an executive vice president and popular spokesperson at Market America, a multinational marketing and product brokerage company based in Greensboro, N.C., and part-owner of the online shopping site shop.com.

YouTube is loaded with his motivational and sales videos, and his full-speed-ahead attitude on the football field followed him into whichever corner office he worked. “Some days are better than others,” he liked to thunder at Market America conventions. “But it’s always good.”

In the 1990s, while his two daughters went to high school there, he was a well-liked and generous assistant football coach and booster club president at Walter Hines Page High School in Greensboro. Players at Page flocked to his house for spaghetti dinners. He helped refurbish the school’s weight room and anonymously paid for extra equipment when players couldn’t afford to.

“He cared about people,” said Rusty Lee, the former athletic director at Page who worked with Mr. Franks. “He lit up a room. Kids flocked to him, and would do anything he asked. He made us a better place.”

For years, Mr. Franks played guitar in the Greensboro-based Honey James Band. In 2018, he and former Eagles teammate Vince Papale published The Last Laugh: Vision to Victory, a 200-page testimonial to how they and others overcame adversity to succeed in business and life.

“He had a bigger-than-life personality with a voracious appetite for life and people,” Papale said.

Adversity came to Mr. Franks shortly after his football career ended. He became addicted to cocaine in the early 1980s and pleaded guilty in 1987 to selling it to, among others, former Eagles teammates. He was sentenced in 1988 to 52 weekends in a community treatment center, two years’ probation, and 300 hours of community service.

A lifelong health nut and gym rat, Mr. Franks was remorseful, overcame his addiction in California, and his business career took off. “His ability to live life and challenge himself to overcome obstacles, and learn from them, and be an example for us and others, was amazing,” said his daughter Lauren Ifft.

Born May 29, 1953, in McKeesport, Pa., 14 miles southeast of Pittsburgh, Mr. Franks was a star in football and track and field at Bethel Park High School and a football star at the University of Michigan. He wasn’t drafted by an NFL team but wound up signing with the Eagles for the 1976 season.

Mr. Franks met Nancy Haslett in South Jersey, and they soon connected in a way that felt deeper than usual to her. “I didn’t know if we’d get married,” she said. “But he was my best friend.”

They did get married, in 1982, had daughters Lauren and Katie, and moved to North Carolina when he joined Market America. Away from work, Mr. Franks liked to drive his boat and ride his bike, and he got cranky if he went too long between workouts at the gym.

He stayed up late to watch old movies about Vikings and cowboys, and always seemed to have time to take his three grandchildren to the park or for ice cream.

Recently, knowing that his shoulder, back, elbows, arms, hips, and ankles had all needed serious medical attention over the years, that the danger of brain injuries in football had become tragically apparent, that hindsight sometimes changes perspective, his family asked Mr. Franks whether he would do it again, make all those painful sacrifices for football.

“In a heartbeat,” he told them.

“He was so easy to talk to, so genuine,” said his wife.

In addition to his wife, daughters, and grandchildren, Mr. Franks is survived by a brother, sister, and other relatives.

A celebration of his life is to be held from 2 to 3:30 p.m. on Sunday, Nov. 7, and may be streamed via Facebook Live at https://www.facebook.com/events/1519571791712115.

The family has created a Dennis Franks Memorial Scholarship Fund.