If you thought portobello mushrooms were large, then check out Giant Puffball mushrooms (calvatia gigantea). Well, now you can grow your very own gigantic mushrooms with this cool new Giant Puffball Mushroom Growing Kit. Just mix the included spores (over a billion!), molasses, and salt in 4 gallons of water and then pour it over the ground whereever you want a massive mushroom to grow. These giant puffball mushrooms are fully edible when immature (pure white inside), but you're going to need a big frying pan. This kit also makes a unique gift for mushroom lovers, gardeners, gourmet foodies, or someone who has everything except a humongous mushroom growing in their backyard.