This is a potion made of common graytop mushrooms which the hermit, Pinastri has been using to see the phantom haunting her. She uses her last two mushrooms to brew a potion for Geralt so that he may deal with the phantom. The brew, however, has the interesting side effect of allowing the witcher to speak to animals, and in particular, Rutilia.
- Fantasmi equini
The potion is never actually seen in inventory, only in the cut scene when Geralt uses it.