But over the past 20 months, Callahan has supplemented his costumed character protection duties with a far more ambitious task. The seven-year BayBears employee is curator of the Hank Aaron Childhood Home and Museum, which opened Wednesday amidst a flurry of big-name guests and intense fan interest.
It is a unique and unprecedented initiative in baseball history, as Aaron's childhood home was relocated to the grounds of Hank Aaron Stadium. For now and all time, Hank's house is at Hank's house.
On Thursday, amidst a much calmer atmosphere than the night before, Callahan was able to provide a comprehensive tour of the museum.
On the house: "We have bricks from the original house on display, as well as nails. [Aaron's father] Mr. Herbert built everything in here with salvaged or scrap wood, from houses that had burned down or had been torn down. What he could save, he did. The original house was 25x25: four rooms, front door, a back door and that was it. No windows. But he did the best he could with what he had.
"The wood floors are all original wood, and all the interior walls are original. The exterior walls were built by [local company] Great Southern Wood, who custom built it to match [the original construction].
"On the wall of the kitchen, we have about 10 percent of what Ms. Aaron had hanging in there, I guess what you would call tchotchkes. But her favorites were two plates from the greater Morningstar Baptist Church, that's why those are hanging so high."
On growing up in Mobile: "Hank became an early-to-bed, early-to-rise kind of guy from an early age. One, because he lived in the country and that's what you did. But also, the earlier you got to bed, the greater your chances of getting the middle of the bed. Because when you're sleeping with two brothers, if you're on the outside, you get the covers yanked off you. So he always tried to get in the middle.
"[Aaron] used to listen to Mobile Bears games on the radio, but he couldn't go to the games because he didn't have the money. But when he was 14, he skipped school when Jackie Robinson came to town. Jackie was speaking here in Mobile about segregation and what to do about it. And Hank was soon inspired by that that he said, 'I'll be a big league ballplayer.' And he made a promise to his Dad that he was going to be a big league ballplayer and play on the same field as Jackie Robinson. His Dad had always told him 'there ain't no colored ballplayers.' But Jackie came along and took that excuse away.
"Hank was spotted by the [Negro League] Mobile Black Bears when he was playing softball. Ed Scott signed him up for the Black Bears. [Scott] managed the Black Bears, but also scouted for the Indianapolis Clowns, and as Henry progressed as a Black Bear, Scott sent a letter to Buddy Downs, manager of the Clowns, that read 'Forget everything else about this player. Just watch his bat.'
"We have a picture here that Ed Scott took that shows [Aaron] at the downtown railroad building. He was ready to go to Indianapolis with two dollars in his pocket, two sandwiches, two pairs of pants and his ball and glove.
"Before the 1954 season opener, when [Aaron] was on the big league squad, the Milwaukee Braves and Brooklyn Dodgers went barnstorming through the South and played in Mobile at Hartwell Field. That's when Hank was able to fulfill his promise to his dad. He got a single and double that day, playing in front of the hometown crowd, wearing No. 5.
"We asked him once, 'What made you switch to 44?' He said 'I don't know, I just wanted a bigger number. If I would have known that would be the number of home runs I was going hit in a couple of years, I would have picked 88 instead.'"
On baseball memorabilia at the museum: "We have a copy of [Aaron's] original Louisville Slugger contract from 1952, he was getting 50 big ones for swinging a bat. We have his first contract with Topps [baseball card company], that was another 50 dollars there.
"Moving on from there we get into things that were provided by Cooperstown: His 1959 gold glove, his first silver bat and a 1957 World Series brochure and championship plaque. We also have a commemorative home plate from Milwaukee County Stadium. Commissioner [Bud] Selig saw that and thought it was really cool. 'I remember that,' he said.
"We've got one replica locker for Hank and one for [his brother] Tommie. All of the items in Tommie's locker were donated by his widow, Carolyn. Tommie played seven years in the Majors and was a career .229 hitter. He was perhaps better known for his career managing in the Braves system. He's in the International League Hall of Fame because of that.
"We have an original picture that Cleon Jones just gave to us, a picture of the '69 Miracle Mets outfield taken in May of '69. It has Tommie, Hank, Cleon, Willie Agee and Amos Otis. They were all from Mobile, the original Mobile Boys.
"The home run chase was, of course, a very important time. We have a limited edition "715" bat and the commemorative ticket from the 715 game was one that Hank actually had in his bedroom, standing on a shelf above his dresser. There's a jersey and hat that Hank wore during the chase too.
"From after his career, we have the Jackie Robinson legacy award. That's something that Hank is very proud of, because Jackie was such an inspiration to him."
On the video interviews playing throughout the museum: "We had Hank here for four or five hours about 10 months ago. He took us from his earliest memories all the way to what happened 10 minutes before he walked into the video room. We have him talking about his family life and about living in Mobile from a segregation and economic standpoint."