Isolei Mushrooms are a species of mushroom found in the Underworld first introduced in chapter 44. They are a rare species of mushroom that are hard to find, with some never seeing them in real life. They require a lot of water for their growth and hence are often found near streams or rivers.
They appear to be small short mushrooms with a thick brown stalk, with a orange-red cap with luminous white, cottony undersides. A tuft of luminous white cottony material grows from the center of the upperside of the cap. When in danger, the mushrooms are able to uproot themselves and produce legs from their body to run away.
The mushrooms are used by Azraels and other inhabitants of the Underworld alike to make many different types of medicines, and along with their rarity, are regarding as a precious source of medicine.