Bob-ombs, Koopas, Boos, oh my! The worst that the Mushroom Kingdom has to offer are featured in a faded "Caution" sign print on the front of this black, 100% cotton t-shirt from Nintendo. Oh, and lava too. Don't forget lava. Oh! And toothy plants, and spiked ceilings, and. . . well, maybe it's best just to stay inside.