This holiday season, a new business is booming. For fun or revenge, people are gifting lumps of coal, including “Clumps for Trump.”

Is there someone in the office who drives you crazy? A relative who gives calendars, every year? A neighbor whose dog stops only in your yard?

For that special someone, no need for a fruit cake or fugly sweater. Now you can send lumps of real coal, gift-wrapped with a bow and anonymous note.

Yes, coal—the bad boy of fossil fuels, the bane of environmentalists—gets new life this holiday season as the anti-present for the despised (or those with a sense of humor.)

At least half a dozen merchants, most within the last month, have moved beyond faux coal products that are just blackish soap, sponges, popcorn, or Rice Krispies. They’re marketing cheap lumps of anthracite from the hollows of Pennsylvania and Appalachia with suggested messages such as “You’re fired!” or “I’m pregnant.”

“It’s a cathartic way to bury the hatchet,” says Griffin Van Meter of Kentucky for Kentucky, noting a woman told her ex-boyfriend: “You deserve this more than you know.” Another retailer, Nathan Adams of Send Coal, recalls customers writing: “Behave and stop breaking women’s hearts,” and “Better not miss picking up the dog poop or there will be more of this next year.”

Most orders are pranks, some political. Boston-based Kyle Waring has received orders to mail his “Ship Coal, Yo!” stocking to President Barack Obama at the White House. He’s declined. Another website, Naughty Coal Box, has sprung up to lambast GOP presidential front-runner Donald Trump, urging people to buy “Clumps for Trump.”

“It started out as a joke.”

The lump-of-coal lore has also crept figuratively into the presidential race. GOP candidate and former Hewlett Packard CEO Carly Fiorina has described Trump as a “Christmas gift” for Democratic favorite Hillary Clinton, saying Clinton “will wipe the floor with him.” In contrast, Fiorina said: “I am the lump of coal in her stocking.”

Why coal is considered such a diss is not entirely clear. Some say Santa just grabbed whatever was lying by the fireplace for bad kids, or that poor kids needed coal to heat their homes so rich—“good”—kids got nuts and fruits (before the dawn of plastic princess dolls and violent video games). Brian Horrigan of the Minnesota Historical Society says it might have something to do with A Christmas Carol’s Ebenezer Scrooge refusing to give even a lump of coal to Bob Cratchit, who was freezing in his office.

Business Is Brisk

“We were shocked to see how many people are ordering,” says Van Meter, whose Kentucky-made goods company began selling coal earlier this month. He’s received thousands of orders for the $7 little bow-topped boxes, which he markets as “the gift that’s worse than nothing” at a cost that is “$542 less than an iPhone 6.”

Waring, founder of Atlantic Ventures, started selling small stockings of half-dollar-sized pieces of anthracite in late November. He says his five dozen orders have all come from within the United States.

Australian startup Send Coal, which also launched its business this holiday season, is shipping boxes within Australia and to the U.S. Its website says the product is “good for humanity,” adding: “Every piece of coal we send is a piece of coal that doesn’t get burnt into the atmosphere.”

A retailer on Etsy, an artsy website, sells “washed pieces” of anthracite as Christmas ornaments with the warning that they’re not safe for use by children. “I personally pick my own coal here in Hazleton, Pennsylvania,” the vendor writes. “Gone are the days of the milkman and the ice man but I still want to be your Coal man.”

This business certainly won’t save coal, now on the decline in the U.S. and Europe as cleaner sources of energy gain ground. On Friday, the last deep-pit coal mine in the United Kingdom was slated to shut its door in Knottingley, England.

The anthracite used in the gifts, typically sprayed or washed so it leaves fewer smudges, is often scraps or debris. Adams, a carpenter in Ashland, Pa., gets his from a buddy who hauls coal for a local company and has leftover pieces at the bottom of his truck.

“It started off as a joke” a few years ago, says Adams, whose Send Coal group has the same name as the Australian company. He and his wife, a school teacher, would send pieces to relatives as a prank.

“A bucket of coal sits in our garage,” he says. This year for the first time, he’s received a couple dozen orders for his small burlap bags, and he’s had to re-order shipping supplies. He says some customers have several mailed to their homes so they can use them as stocking stuffers.

For every grumpy order, he says at least five or six are funny. “It reinforces my belief that there are more nice people than naughty ones.”

Does his four-year-old son fear getting a lump of coal? “He’s way too good of a little man,” Adams says. He pauses, adding: “Maybe when he’s a teenager.”