Menecrosium is a rare and unique giant grey mushroom that possesses remarkable properties related to necrotic and psychic energies. It can only be found in specific locations, often in dark and shadowy environments. The mushroom's distinctive appearance, with its large cap and intricate gills, distinguishes it from other mushrooms.
When consumed, Menecrosium grants temporary immunity to necrotic damage and provides advantage on saving throws against psychic damage for the duration of 1 hour. The mushroom's unique composition allows it to absorb and neutralize the harmful effects of these particular energy types, enhancing the consumer's resilience against them. This property makes Menecrosium highly sought after by adventurers, spellcasters, and those who frequently face enemies that wield necrotic or psychic abilities.
However, it is important to note that Menecrosium has an adverse effect when consumed by undead creatures. Instead of providing benefits, it inflicts disadvantage on saving throws against necrotic damage and removes any existing immunities or resistances to psychic damage for the duration. The mushroom's inherent anti-undead properties make it a potential tool for combating undead adversaries, as it turns their own vulnerabilities against them.