Spirit moss

Spirit moss smells like death and tastes worse than decaying flesh. It is a gray-green and grows in patches on dead trees. Once ingested, it allows someone to speak to the dead in the area, making it valuable to those searching for the dead's secrets. This power doesn't come for free however. When eating the moss, the user gets these powers and sharpened senses, but sacrifices some of their speed and strength as the body is severely weakened.

The Golden Oasis in the city of Katapesh has a patch of spirit moss growing on a dying palm tree. When nomads eat from this patch of moss, they sometimes meet a spirit that stays close to the oasis, mistaking it for a messenger from the gods.