Unicorn

"Only one who has nothing to lose, and everything to gain, would commit such a crime. The blood of a unicorn will keep you alive, even if you are an inch from death, but at a terrible price. You have slain something so pure and defenceless to save yourself, you will have but a half-life, a cursed life, from the moment the blood touches your lips."

- Firenze to Harry Potter

The unicorn is a white, equine creature with a single horn on its forehead.

Physiology and life cycle
Unicorn foals are born pure gold in colour. They remain so until they are about two years old, at which time they turn silver in colour. At around four-years-old their horn grows in. They are fully grown at about seven years old, at which at this age they turn a shade of pure white that is so bright that it makes freshly fallen snow look grey in comparison. Their hooves are golden, (remaining so from their gold stage, (the first two years of their life)), and their blood is silver-blue in colour and shines under the moonlight. It is not mentioned how long a Unicorn can live for.

Distribution
Unicorns inhabit the forests of Europe, including the Forbidden Forest by Hogwarts.

Interaction with humans
Unicorns prefer a woman's touch, but the young ones are more trusting and do not mind men as much. Unicorns are also so fleet-of-hoof that they can rarely be caught by humans.

Uses
Various parts of the Unicorn - the horn and tail hair in particular - are used in potions. Unicorn hair in general is used for the cores of wands. The tail hair can also be used as binding in bandages due to its incredible strength. The blood of a unicorn can be used to keep a person who is near death alive, but "you will have but a half-life, a cursed life, from the moment the blood touches your lips."

The unicorn's single straight horn is used, in runic, to symbolise the number one.

1992
At least two unicorns were slain by Quirinus Quirrell so Lord Voldemort could drink their blood and return to power. Harry Potter, Draco Malfoy and Fang found the corpse of one of them in the Forbidden Forest.

1995
In 1995, fourth year students at Hogwarts School of Witchcraft and Wizardry studied unicorns in their Care of Magical Creatures class, while Professor Wilhelmina Grubbly-Plank was standing in for Hagrid.

Behind the scenes

 * In LEGO Harry Potter: Years 1-4, Voldemort tries to sneak up on the unicorn with a knife and fork, but is scared off by Firenze who shows him his fist. Hagrid then proceeds to care for the sick unicorn like a child.
 * Unicorns are capable of moving faster than werewolves. During the detention in the Forbidden Forest in 1992, Harry asked if a werewolf could be killing the unicorns and Hagrid replied that they're not fast enough.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Philosopher's Stone (film)
 * Harry Potter and the Chamber of Secrets
 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Prisoner of Azkaban (video game)
 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Goblet of Fire (film)
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Half-Blood Prince (video game)
 * Harry Potter and the Deathly Hallows
 * Fantastic Beasts and Where to Find Them
 * J. K. Rowling's Official Site
 * LEGO Harry Potter: Years 1-4
 * Harry Potter Trading Card Game
 * Pottermore