Now that’s one humongous fungus!

A record-breaking white truffle weighing 4.1 pounds is going up for auction at Sotheby’s in Manhattan this Saturday.

The giant tuber — which is about the size of football — was dug up last week in Umbria, Italy, by a truffle-hunting dog that works for Sabatino Tartufi Truffles. An average truffle is about the size of a walnut.

“The hunter was speechless when he found ‘Big Boy.’ The smell was intoxicating,” Giuseppina Balestra, a co-owner of Sabatino, told the Times of London.

The mammoth truffle has already attracted Chinese buyers willing to pay $1 million. The winner will have to go from auction block to chopping block: This Big Boy will rot within 20 days.

All auction proceeds will benefit Citymeals-on-Wheels and the Children’s Glaucoma Foundation.