Unicorn

Unicorns are mythical beasts from an unknown Magical Realm.

They are described as the essence of good magic and their horns are pure concentrated magic. When dust is scraped off their horn, it can be used to empower spells and powers and to vanquish evil beings, even when no other magic is available.

History
Shorty before the birth of Wyatt Halliwell, the Halliwell Manor was showered with gifts from the magical community. Among the gifts was a Unicorn with a card around its neck saying it was from "From El". Paige originally believed it was sent by someone in Spain, though after magic had disappeared, Phoebe reasoned it had come from the Elders instead to help them.

The sisters used the dust from the Unicorn's horn to vanquish Cronyn, Doris, and Stanley, who had attempted to steal Piper's child. Leo also used some of it to heal Victor Bennett's wound.