Shroomtoo Share definition Flag A redish tatoo a girl gets after hitting them over and over in the same spot with ur penis,causing it to turn red in the shape of a mushroom. I would love to give that chick a shroomtoo right on her ass. Shroomtoo by zacklwwb December 2, 2007 0 0 Get merch Get the Shroomtoo mug. Buy Now — $32.95 See more merch