Mysterious black liquid

There exists a potion that is described as a black liquid, the surface of which gleams like ink. Its effect when consumed is unknown, but breathing in its fumes causes one to see strange visions.

Behind the scenes

 * This potion is only mentioned as a possible answer to a hypothetical question posed during the sorting quiz on Pottermore. Therefore, it is unclear if a potion like this truly exists.

Appearances

 * Pottermore