Kuswort

Kuswort is a fan-created plant from the Harry Potter fandom. Ironically, it is the essential ingredient in the cure for the Mary Sue disease, Vambiolaria, which was created by a fan-made spell gone horribly, horribly wrong.

Kuswort has yellow foliage and smells like vomit. Its use was discovered and put to use at the Hogwarts Fanfiction Academy.