Amanita fuliginea, commonly known as the east Asian brown death cap, is a species of deadly poisonous mushroom in the family Amanitaceae.

The fruit bodies have convex, dark gray to blackish caps measuring 3–6 cm (1.2–2.4 in) in diameter.

[3] The deadly α and β amanitins have been isolated from this fungus alongside an additional unidentified phallotoxin.

[4] Findings indicate that the concentrations of amatoxins and phallotoxins in A. fuliginea vary among its tissues and developmental stages.

Toxin levels were found to be highest in the gills, with peak concentrations occurring during the fruiting body's vigorous growth stage.