Witch's Magic Potion Necklace

Always keep a vial of magic potion close. What does it do? Only the witch knows.

This small 6cm by 3cm glass bottle is filled with a mysterious green liquid that glows in the dark. The bottle is corked and sealed, labeled with a black sticker that says 'Magic Potion'. Attached to a silver coloured crescent moon, this potion hangs from a 71cm long faux leather cord that can be worn around your neck.