A Halloween Academy Apothecary Product
Essence of Black Cat
"The properties of black cat fur are well known to all skilled witches. This bottle contains, not only fur of the black cat, but a portion of its soul.
Guaranteed to give any curse that extra vindictive kick, Essence of Black Cat can also be used as a catalyst in transformation spells. Simply mix one part Essence of Black Cat to 10 parts of another spell or potion and, if it goes awry, the potion will default to a black cat transformation spell, easily reversed with some elementary incantations."
And, yes, the artist is aware that Essence is misspelled. What can I say? Witches are eccentric spellers.