Among the biggest fans are young people who were not old enough to drink - or in some cases not even born yet - when National Brewing Co. closed down in 1980.
National Bohemian went on to be produced by Stroh Brewing in Halethorpe until 1996, and, since then, by Texas-based Pabst, but it is still marketed regionally. Outside Maryland, Mr. Boh remains fairly unrecognizable.
Citro said out-of-towners often mistake Mr. Boh for Mr. Pringles, the round-headed, mustachioed (but two-eyed) potato chip mascot.
Actually, Mr. Boh, who dates to the 1930s, could be his grandfather.
He originally appeared in National Bohemian advertisements among an ensemble of characters, a sophisticate wearing a top hat and monocle.
After that, he took center stage, but his face became more of an oval. In the 1950s he first appeared as the Mr. Boh we now know - round head, one eye, bushy mustache. The face was always the same, except for his lone eye switching from one side to the other. Sometimes he was a bartender, sometimes a waiter, sometimes a baseball player, among other things.
"I still remember the print ads - back when radio was in its infancy and TV wasn't even here yet," said Bill Costello, 71. "There was Mr. Boh, with the one eye, and the hyphens coming out of the eye going into the bottle of National Bohemian, and the words, `Oh boy, what a beer.'"
In the mid-1960s, Costello would go to work for National Bohemian, serving as director of advertising from 1964 to 1975. But Mr. Boh would leave.
"We had a red label that had been virtually unchanged since Prohibition, and in 1965 it was changed to a white one, because top management felt the white label would say `lighter taste,' and lighter tastes were becoming popular," Costello said. At the same time, Mr. Boh's likeness was removed.
"We screamed and yelled and fought. ... We didn't want it changed," Costello added. "We were on top of this market, by far, when that label was changed. After that, you could see our sales on the graphs just drop off."
Eventually, Mr. Boh was returned, he said, but the label change hastened the demise of National Bohemian, which once accounted for three of every five beers sold in Maryland.
As the popularity of national brands such as Budweiser increased, bolstered by heavy TV advertising aimed at snagging younger drinkers, sales of regional brands steadily declined, among them, the beer brewed in "the land of pleasant living."
As to Mr. Boh's recent resurgence, he said, "I think it's just Baltimore nostalgia. Why did Volkswagen bring back the Bug?"
Costello is one of five former National Brewing Co. employees who relive the brewery's glory days in a documentary sponsored by Struever Bros. and Obrecht Commercial Real Estate Inc. - developers of two defunct breweries on Conkling Street, National Brewing and Gunther Brewery.
The 27-minute documentary is the result of nine hours of interviews with the employees and "Turkey" Joe Trabert, a Natty Boh aficionado and former bar owner, and features archival photos and footage of old advertisements.
The Creative Alliance is premiering the documentary tonight at the Patterson, but, despite adding a second show, both are booked to capacity.
"They definitely tugged some heartstrings with this," said Megan Hamilton, program director for the alliance. "The response has been huge." The alliance is considering additional showings.
The filmmakers plan to make a shorter version to be shown in the Natty Boh Tower lobby, and perhaps a longer one as well.
"There was so much we couldn't get in," said Harry Connolly, director of photography. That includes recollections of the days employees would hunt pigeons in the brewery. Whenever one was shot and fell into the beer vat, that batch wouldn't be sold to the public, Connolly said. But, he added, it was shared by employees, who referred to it as "pigeon beer."
Artist-architect Alex Castro headed the documentary project, and with developer Bill Struever came up with the idea for the neon Mr. Boh sign - appropriately enough, over a beer.
"We kind-of thought, `Wouldn't it be wonderful on top of that tall building to put a big Mr. Boh?' And I guess it was about half a beer later when we said, `Wouldn't it be great if he winked at the city?' " Castro said.
The Mr. Boh sign atop 3601 O'Donnell St., visible from Interstate 95, winks about once a minute.
"It's just such a beautifully compelling design - so unique and strong and immediately recognizable, and it has a warm feeling to it," Castro said. "It's just a friendly face."
Mr. Boh's comeback, though, is about more than that. He's kitschy and oozes nostalgia, but mostly he's a reminder of simpler times in a city that seems to appreciate those reminders - maybe more than most.
"Baltimore has a great sense of memory," Castro said. "We remember the Colts, all the early Orioles, and all the cherished old places from years ago, like Haussner's [restaurant], that were part of us. So when you bring something back like that, it's magical. It relates to something deep in our hearts."
To see a clip from "Mr. Boh's Brewery," go to baltimore sun.com/nattyboh.