The Old Kingdom
Red caps / Mad caps
A mushroom that causes hallucination. heavy users claim that the drug connects you to the gods. Users are know to become unresponsive and simple wandering about in a zombie like state. Those that have died by over consumption often leads to mad caps growing from the corpse.
The mushrooms have been outlawed in the Eastmarsh Empire. It is believed that various thieves guilds in particular the Clan of the Ravens Feathers are responsible for the continuing popularly