"Are you serious?" said Prudence Onesto, her eyes widening. "Really?"
"Secret Santa," he deadpanned, breaking into a broad grin.
The 55-year-old unemployed woman opened her arms and offered him a hug.
An aisle over, 41-year-old Janice Kennedy was overwhelmed: She received four $100 bills.
Unemployed with a 2-year-old daughter, she lost her home in the storm and lives with her boyfriend. The money will go toward Christmas presents and her toddler's next birthday.
"You're not alone. God bless you!" the Missouri stranger told Phillip and Lisa Morris, a couple in their 30s whose home was badly damaged — but now had an extra $300 in cash for rebuilding.
Secret Santa took up the holiday tradition from a close Kansas City friend, Larry Stewart, who for years handed out bills each December to unsuspecting strangers in thrift stores, food pantries and shelters. Stewart died in 2007 after giving away more than $1 million to strangers in mostly $100 bills.
The current Secret Santa will not divulge his name. Nor does he allow his face to be photographed. But he said he's been to cities across America, from San Diego to Chicago to Charlotte, N.C.
A reporter asked whether he might be a sort of Warren Buffett of Kansas City. He smiled mysteriously and said only that he admires Buffett for his philanthropy. "And I hope I give all my money away before I die."
Then, as suddenly as he arrived, the generous stranger left for the airport and home, riding in the volunteer motorcade he jokingly calls "my sleigh," zipping with ease through red lights and city traffic.