Around Christmastime, Slattery, 68, can be identified wearing the iconic red stocking cap at a handful of local schools, the bus barn, or family homes. Like any good Saint Nicholas, Slattery takes pride in bringing enjoyment to people for Christmas.
"I'm a people person," he said. "I get a kick out of making people laugh."
Dressing in the red suit, bells on his wrist, and a pillow for a stomach allows him to do just that. He always aims for a grand entrance and loves to see the reaction on kids' faces.
"If I can give them a little bit of giggles and cheer them up a bit. That's the part I like about it the most," he said.
It all began when the Northeast Wyoming Board of Cooperative Educational Services was having a difficult time finding a Santa Claus in 2009.
Slattery and his family have been familiar with the school for years. The daughter of he and his wife, Nancy, attended the school as a student. Another daughter currently works there as a nurse, and Slattery worked as a cottage parent for eight years.
When BOCES couldn't find a Santa, he stepped in and has been doing it ever since.
"That's where it all started, but then word gets out," he said.
It's not just the schools. Several neighbors have asked him to bring presents to their house. He has fond memories of delivering a puppy to a young boy a couple years ago.
Working as a substitute bus driver for the Campbell County School District made it easy for him to be Santa at its annual holiday party. Some of the older kids recognize him from driving the bus, but Slattery said the little ones think it's the real deal.
There's a reason why shop manager Frank Latta thinks Slattery looks like Kris Kringle when he is driving the bus. That's because his beard is as authentic as it gets. He has been growing it for 40 years.
"I get a lot of compliments for my beard. Everyone wants to feel it," Slattery said, "I joke and tell everyone it takes a lot of Miracle-Gro."