 A large , conspicuous mushroom , Amanita muscaria is generally common and numerous where it grows , and is often found in groups with <unk> in all stages of development . Fly agaric fruiting bodies emerge from the soil looking like white eggs . After emerging from the ground , the cap is covered with numerous small white to yellow pyramid @-@ shaped warts . These are remnants of the universal veil , a membrane that encloses the entire mushroom when it is still very young . <unk> the mushroom at this stage will reveal a characteristic yellowish layer of skin under the veil ; this is helpful in identification . As the fungus grows , the red colour appears through the broken veil and the warts become less prominent ; they do not change in size , but are reduced relative to the expanding skin area . The cap changes from <unk> to <unk> , and finally to plate @-@ like and flat in mature specimens . Fully grown , the bright red cap is usually around 8 – 20 cm ( 3 – 8 in ) in diameter , although larger specimens have been found . The red colour may fade after rain and in older mushrooms . 
