Tina Beznec, from the city of Lower Hutt, is auctioning space on her backside to be tattooed with a design of the winning bidders choice in an online auction.
The listing has become a viral hit, attracting more than 170,000 hits and bids of more than $8,600 - Ms Beznec plans to give 20 percent of the proceeds to charity.
She says the winning bidder will win the right to have whatever they like tattooed on the 9x9cm patch of skin, adding: "I'm just trusting the winner of the auction will not do anything too stupid."
"I think it's amazing that, you know, it's gone global. Gone viral over the internet. Several different countries have tried making contact with me. Everyone's talking about it. It's quite a big topic. So, yeah, it's awesome," said Tina. So far, design proposals include brands and promotions, "property of..." tags and self-portraits.