It's a Lion's Mane mushroom! Grown from a mushroom-growing box from Segura and Sons, a mushroom farmer in Stevens Point.
Two weeks ago, we bought a Lion's Mane grow box from Segura, who sells mushrooms and kits in the Stevens Point downtown Saturday morning farmers' market. Lynn found a good place in the basement, asked me to spritz in the box in the morning and leave the light on until 6 PM.