Bewilder Berries

Bewilder Berries are a dark blue berry found on small bushes close to ground level, often in fields or clearings. They are extremely similar to other edible berries, and normally appear similar to a mix between a blueberry and a blackberry. However, they are tricky, as they have been known to change how they appear to entice their prey. They grow throughout the year, except for during with month of Felnight, when their bushes do not sprout berries.
Despite looking and tasting similar to many other edible berries, Bewilder Berries are highly toxic and can incapacitate even people of even the highest constitution. It is not uncommon for someone who consumes a bewilder berry to be fully incapacitated for an entire day, entering a not fully conscious but not fully unconscious state.
Bewilder berries grow throughout the temperate lands of the continent of Calradia.

In mechanical terms, on consuming a Bewilder Berry, a creature must make a DC 12 Constitution Save, or be stunned for D20 hours, adding +1 to the number of hours for every number between their save number and the DC.