Dreamdeath
Dreamdeath or "Dreamer" is "a strange hallucinogenic lichen" that grows above the treeline in the Claedesbrim Bay (Modern: Darkstone Bay) region. In its benign form it will cause extremely pleasant visions when ingested, and is thought to have restorative properties. In its other form it causes terrifying delirium and often results in death. There is no way to tell the difference between these variants. It is believed the benign form is the result of higher altitudes or some difference in the quality of light. It is still present in the background descriptions of GemStone IV, but does not mechanically exist.
I.C.E. Age Example
There is "Dreamer" lichen on the path to Cavernhold, which was originally the gnoll settlement called Stonehold:
>w [Alpine Meadow] This serene meadow is deep within the mountains and slightly southeast of the rugged peak known as Lyftoth. The wildflowers that grow here are fragrant and plentiful. Traesharm berries grow in startling abundance and small patches of the strange Dreamer lichen can be seen clinging to a few of the exposed rocks. Obvious paths: east, northwest
This room was inconsistently De-ICE'd. Traesharm was originally flaeshorn, but Lyftoth is the original name of the mountain. To the west it is called Zeltoph, but then to the east what was probably Hetoth is also called Zeltoph. This stretch used to incur round time with messaging stating that you were traveling for a great deal of time and making camp between the foothills and Cavernhold.