Benny the mystery philanthropist hides $100 bills. So far, he’s given away more than $55,000.

It happened two summers ago, as Joe Robinson was marking down the prices on the pots he was selling at a fine arts festival in Oregon.

“I pick pots up by the rim, flip them upside down, see if the price looks right, maybe cross it out, put something else,” Robinson told The Washington Post on Friday.

Regular, everyday stuff, you know?  On that day in 2014, though, he picked up a pot that had an imprint of a fern on it.

He flipped it over.

And as he did, out dropped a $100 bill, upon which a name was written: “Benny.”

“It was a brand-new, crisp $100 bill that had obviously never been in circulation,” Robinson said. “So that mark was pretty obvious on it.”

Robinson figured it was some kind of mistake. Maybe someone dropped it by accident when they were making a purchase earlier in the day.

Because you don’t just find a hundred bucks, right?

But remember that name on the bill? It indicates the money came from a person known simply as Benny — a mysterious philanthropist who has anonymously hidden hundreds of $100 bills over the past few years.

And the people Robinson spoke with after finding the cash knew all about it.

“Everyone had some kind of a story,” Robinson said. “And so I guess it’s his thing to do crisp, brand-new bills.”

“Benny” hides those $100 bills all over the place in Salem, Ore., and the surrounding area, reports have indicated. They have been discovered in the pockets of clothing, in diapers, in baby wipes and in candy, Capi Lynn, a columnist for the Statesman Journal, said in an email.

“As of today, he has given away more than $55,000, and that’s only what has been reported to me,” Lynn said in an email to The Post. “I have a feeling Benny will be at it until his identity is revealed, or he can no longer do it for some reason.”

Lynn’s newspaper, in Salem, Ore., tracks the Benny finds; she gave him the nickname (Get it? As in Benjamin Franklin?), and first wrote about him in 2013 after some Cub Scouts reported finding folded $100 bills.

In the past few years, the newspaper has been able to document all sorts of stories about Benny and his gifts.

There was the girl who found a Benjamin in a pink bank purchased by her mother.

“I shook it, and it popped out of the hole,” the girl said. “My mom thought it was fake, but it was real.”

And the woman who found one with a package of cereal, right when she truly needed it.

“It just made my day,” said the woman, Tammy Tompkins. “I cried happy tears for about an hour and a half.”

The Statesman Journal reported that Tompkins’s husband had been struggling with health issues for some time when she found the money left by Benny.

“I’d just like to tell him — oh, gosh, I’m going to cry — just how much that it touched us, how much we appreciated it,” she told the Statesman Journal. “We’ve been through so much.”

In another instance, Benny’s gift was discovered by an 8-year-old boy who found the cash in a store’s toy bin. The newspaper reported that the boy and a friend who was with him would use the cash to buy toys.

But not for themselves. The plan was to donate the haul to a children’s group. What’s more: Their parents were expected to match Benny’s gift, according to the Statesman Journal.

This is a thing that happens a lot, said Lynn.

Benny, she wrote, has “launched a pay-it-forward spirit in the community.” By her estimation, more than half of those who find his $100 bills end up “paying it forward” — either to a charity of their choice, a cause dear to their heart or just to a person or family needing it.

“The people who need the money are spending it on things like groceries, gas and prescriptions,” Lynn wrote. “Those who pay it forward are spreading the cheer to a variety of local nonprofits and organizations, with food banks, animal-rescue groups and schools the top three pay-it-forward recipients. Benny finders also can be very creative with how they pay it forward. One woman keeps a box of sack lunches in her car to hand out to panhandlers, and she used her Benny to fund her mission for a time.”

Robinson had once hiked the Pacific Crest Trail and remembered one spot in particular, in Oregon.

He thought of what he wanted there during his hike — taco salad, beer, ice cream, cake. So he used the money he found to make that happen for a few lucky people on the trail.

“I just thought it would be cool to do something unexpected that would be super thrilling,” he said.

Robinson hauled slow-cooked pulled pork tacos, sheet cake, ice cream, soda, beer and whiskey out to a campground. “I think I also got some fruits and vegetables,” he said. “Some people actually want healthy food.”

Then, he said, he waited for hikers to happen by.

“It really made a few people’s day,” he said.

About nine hikers came through and benefited from Robinson’s generosity that day. By extension, they benefited from Benny’s, too.

“A lot of agape mouths,” said Robinson, who said the gesture “seemed like a fitting way to make people happy unexpectedly, like Benny did for me.”

When asked about Benny’s anonymity, Robinson said he believes that some people have figured out the mystery. They’ve seen him make the drops, he said — but they’re keeping their mouths shut.

“I think that the people that have found out have probably been touched by his motivations,” Robinson said. “It’s like, ‘Hey, I believe in this, and your secret’s safe with me.’ ”