When it comes to the holder of the title of “World’s Largest Living Thing,” it’s a cinch that it must be the blue whale, right? Wrong.

The actual holder of that title is likely a mushroom of the species Armillaria ostoyae in the Malheur National Forest in Oregon. It covers 2,200 acres and is between two thousand and eight thousand years old.

Most of it is underground in the form of a massive mat of tentacle-like white mycelia (the mushroom’s equivalent of roots). These spread along tree roots, killing the trees and peeping up through the soil occasionally as innocent-looking clumps of honey mushrooms. While an accurate estimate has not been made, the total weight of the organism may be as much as 605 tons, making the blue whale, at a measly 190 tons, a comparative 90-pound weakling.