Nightshade Lovelycoat is a unicorn that might be friends with Marigold Heavenly Nostrils. She was mentioned in a gossip of Marigold's in the first book when Phoebe and Marigold were having a sleepover.
It is unknown what her appearance is, since she was only mentioned and never made an actual appearance.
She has a horn extention.
She is the first charecter to never make an appearance.