"I was like so, 'are you going to bring that back or are you taking that as a souvenir?'" Harper told WDJT-TV.
The woman apologized and put the snowman head down, according to a police report. When Harper asked if anyone in the group would pay for the damage, the man got confrontational.
Police responded and identified the trio as having been at a bar earlier in the night. Michael and Melisa Koehler and Sara Alswager were cited by South Milwaukee police for damage to property.
The case took a surprising turn when the three vandals later showed up at Harper's door.
"They came over the next morning, and they apologized, which I was kind of surprised about," he said. "And they gave us $50 to replace it."
Harper said he understands people make mistakes. He's since replaced the headless snowman with one that he hopes stays intact.