But with his sloping gut, fluffy beard and straw hat, he cut a striking visual. And eventually his O-R-I-O-L-E-S cheers, replete with dramatic contortions of his out-of-shape body, became the emotional fulcrum as crowds at Memorial urged the baseball team to improbable comebacks in the late 1970s and early 1980s.
Mr. Hagy, a cabdriver in everyday life, died yesterday at his Arbutus home. He was 68. The cause of death had yet to be determined.
Many trace the birth of "Orioles Magic" to June 22, 1979, the day a Doug DeCinces home run gave the eventual pennant winners a come-from-behind victory over the Detroit Tigers. Mr. Hagy cheered that moment and many more.
"For a team that didn't draw very well, it was very refreshing to see someone who actually came out to the ballpark and generated interest," said Orioles Hall of Fame pitcher Jim Palmer. "He loved the Orioles. And I'm all for people who are in that category."
"Of course, it was unbelievable," said longtime friend George "Skip" Dorer, who met him while working on a book about the 1979 Orioles. "That place rocked, and he was at the center of it."
Mr. Hagy became such a fixture that he was allowed to climb atop the Orioles' dugout to rally the crowd with his act. He was so popular that all he had to do was stand in his section to get the crowd roaring. For a generation of Orioles lovers, he was the quintessential fan.
"He'd say he was just going to get a beer or go to the bathroom," said Wayne Kaiser, his friend of almost 30 years and roommate, "but then, all of a sudden, you'd see him up on the dugout leading cheers."
He met Presidents Jimmy Carter and Ronald Reagan, was written up in the New Yorker and signed more than his share of autographs.
"To those of us who were close to him, we were sort of enthralled to be around this famous guy," Mr. Kaiser said. "He never got a big head about it. But he enjoyed how the fans responded to him. He was a die-hard hometown guy, and he liked that he could get people excited about the team he loved."
The Orioles had planned to observe a moment of silence in his memory last night, but the game at Camden Yards was rained out.
"The Orioles organization is deeply saddened to learn of the passing of 'Wild Bill' Hagy," the club said in a statement. "While leading cheers from 'The Roar from 34' at Memorial Stadium, Wild Bill became a Baltimore institution. ... He will be missed by everyone who knew him and by everyone for whom he led the 'O-R-I-O-L-E-S' cheer. All of us in the Orioles organization extend our sincere condolences to his family and friends."
Former Orioles catcher Rick Dempsey would sometimes join Mr. Hagy on the dugout to lead cheers. If Mr. Dempsey thought the team needed a lift, he'd signal Mr. Hagy by waving a white towel from the bullpen. Wackiness usually ensued.
"I just remember how much control he had over the crowd," Mr. Dempsey said. "In an era when the Orioles were on fire, he turned the crowd on fire. He was a huge part of the Orioles Magic era."
Mr. Hagy was born on Sparrows Point and attended Sparrows Point High School.
He began attending Orioles games with his father during the team's first season in 1954.
"Brooks and Frank Robinson, Jim Palmer, Rick Dempsey, he loved them all as long as they were loyal to the Orioles," Mr. Kaiser said.
As a young man, Mr. Hagy drove an ambulance and then a Good Humor ice cream truck. But for most of his professional life, he drove a taxi for Jimmy's, County and North Point cab companies. He retired in January 2004.
"He enjoyed being his own boss," Mr. Kaiser said. "He could work as little or as much as he wanted."
If ever an out-of-town fan happened into his cab wearing a Yankees hat, he ordered it removed. If the person refused, he refused the fare.
Away from baseball, Mr. Hagy loved the Grateful Dead, the blues, classic country and bluegrass. He played golf and later, when his health worsened, online poker. He retained loyal friends from Dundalk and Arbutus, and spent his later years sipping Budweiser and playing Keno with them at Leon's Triple L Restaurant & Lounge on East Drive in Arbutus.
"He was a happy dude," Mr. Kaiser said. "Give him a Budweiser, a lounge chair and a game, and he was content."
Marilyn Karr bought a date with Mr. Hagy in a fundraiser for the Johns Hopkins University Chaplain's Office's literacy program. Mr. Hagy took her to a sports banquet in Towson where he wowed her with knowledge gleaned from the many newspapers and magazines that had been left in his cab over the years.
"He was one of the kindest, gentlest, most considerate people I've ever known," she said. "You might think otherwise with the burly build and the beard and the cut-off jeans, but he was just a wonderful man."
At the ballpark, fueled by Budweiser and his love for baseball, he became a different person. Mr. Hagy took his inspiration from legendary Baltimore Colts fan Leonard "Big Wheel" Burrier. He once asked Mr. Burrier if he minded an imitator at Orioles games. "Big Wheel" gave him his blessing and thus began the routine.
Mr. Dorer and Mr. Kaiser remembered watching him lead cheers from the bottom of his section as early as 1977. He had a whole repertoire, one for each Orioles star. "Come on Ken, hit it in the pen," he'd chant for Ken Singleton, who sometimes responded by driving balls into the bullpen.
Mr. Palmer said Mr. Hagy was the perfect fan for Baltimore.
"This was a football town when I got here," he said. "The Colts were still the No. 1 team in this town. But he was like everybody else. He was kind of the cheerleader version of Cal. I think people could relate to him. People loved to sit up there. ... He made it exciting."
For a while in the late '70s and early '80s, Mr. Hagy attended every Orioles home game with his crew from Dundalk.
"It was such a wonderful place to go," Ms. Karr said of the section. "It was like a family. They kept track of each other. They knew your parents, your siblings, your love life, who needed help. And, of course, Bill was the ringleader."
Mr. Hagy's celebrity "got to the point where so many people were coming up the steps to see him that he couldn't see the ballgame," Mr. Kaiser recalled. "And that was the most important thing to him. He would ask the ushers to help cut the flow back a little so he could see the game."
In 1985, Mr. Hagy began a boycott of Memorial Stadium because he was no longer allowed to bring his own beer in a cooler. The night before the ban went into effect, he downed nine or 10 beers by his count and then launched his empty cooler from the upper deck onto the field.
He was also distressed at the declining state of the team.
The Orioles tried to bring him back to lead a last cheer during the final game at Memorial Stadium in 1991. But he turned down the request, continuing the boycott.
He returned, far more quietly, a few years after the team moved to Camden Yards.
He was there Sept. 6, 1995, when Cal Ripken Jr. played in his 2,131st consecutive game. After Mr. Ripken took his lap along the outfield wall, Mr. Hagy led his signature O-R-I-O-L-E-S chant. "This is probably the most amazing love-in you'll ever see in Major League Baseball," he said that night.
Last month, Mr. Hagy traveled to Cooperstown, N.Y., on a bus to watch Mr. Ripken's induction into the Baseball Hall of Fame. There, he led one last cheer for the fans sitting on the hillside with him.
Mr. Hagy continued to attend Orioles games at Camden Yards until this year. "I don't think most of the people around me know who I am," he told The Sun in 2004, "and that's OK; I kind of like it that way."
Mr. Kaiser said that no services will be held but that friends are planning a party to celebrate Mr. Hagy's life.
Survivors include three children, whose names were not available, and two sisters, Carole Tyree of Stewartstown, Pa., and Mary Lou Hollett of Alexandria, Va.
In more personal moments away from the park, Mr. Dempsey rode in Mr. Hagy's cab and talked baseball with him.
"He was just a thrilling part of our careers," Mr. Dempsey said. "There will never be another like Wild Bill Hagy."
Sun reporter Roch Kubatko contributed to this article.