(CNN) -- During a family trip to the beach last month, 4-year-old Paul Franklin fell and scraped his right knee.
That's not unusual; little boys do all the time.
It's what emerged from his swollen knee that makes this a tale worth telling: a snail.
Paul of Aliso Viejo, California, was walking along the beach when he dinged his knee against a rock.
"We just cleaned it up, put a Band-Aid on it," his father, Ken Franklin, told CNN affiliate KCAL. "Before you know it, a couple weeks later, his knee was very swollen and somewhat infected."
A doctor told Paul's mom, Rachael, that it might be a nasty staph infection. Antibiotics helped, but there was a growing black bump underneath the skin.
Tired of waiting and certain the wound needed to be drained, the mom decided to take matters into her own hands. She squeezed it with her fingers and out it popped.
"It looked like a rock. It was a black thing," she told the station. "I put it on a paper towel and I'm like, 'That is a weird looking rock. It has swirls on it,' and I turn it over and it is a sea snail."
The family figures a snail egg got under Paul's skin when he scuffed up his knee.
And little Paul's reaction?
"I thought it was kind of crazy," he said.
But not so crazy that the preschooler didn't take ownership of the find.
The Orange County Register reports that Paul named the snail Turbo, after the star of this summer's animated feature.
CNN's Dorrine Mendoza contributed to this report.