The Nymph was available for purchase through the Geek Store (now out of stock).
From the product page:
"The wilderness surrounding the kingdom is rumored to contain many mysterious and wondrous things, but rare is the day when one of them makes its presence known. The Nymph has strange and potent abilities linked to the cycles of nature, and motives that few men might guess, but any ally against the Necromancer is welcome in the kingdom today."
This is a special, promotional package that is being offered exclusively to BoardGameGeek for six months (as of April 15th, 2013). This package includes the Nymph along with 10 power cards, plus a new event and an artifact. This is a must-have for all Darkest Night fans!
This game requires Darkest Night
Game Components:
• 10 Power cards
• 1 Artifact card
• 1 Event card
• 1 Hero card
• 1 character tracker (minor assembly reqired)