Blood

"'Family,' said Hagrid gloomily. 'Whatever yeh say, blood's important…' And he wiped a trickle of it out of his eye."

— Hagrid mopes at the Three Broomsticks Inn while suffering injuries caused by Grawp in 1996

Blood is a liquefied substance in some organisms, like humans, that carries oxygen throughout the body. In some creatures, blood was known to possess magical qualities.

Blood in the wizarding world

• Weakness payment required blood to be shed.
• Blood pact involved the mixing of blood as part of a magical blood oath ritual.
• The blood of a unicorn would keep someone alive, even if they were "an inch from Death".
• Re'em blood gave the drinkers immense strength for a short period of time.
• Albus Dumbledore was known to have discovered the twelve uses of dragon blood.
• Some creatures, like ghosts and inferi, had no blood, because they were dead.
• Chicken blood mixed with brandy was fed to baby dragons every half-hour.
• Some wizarding terms and nicknames used the word blood. They included:
  • Half-blood
  • Pure-blood
  • Mudblood
  • Half-Blood Prince
  • Bloody Baron
  • Blood Quill
  • Blood traitor
  • Blood status
  • Blood brothers
  • Bloody hell
• Severus Snape was known as the Half-Blood Prince and invented the curse Sectumsempra, which lacerated the target, causing it to shed much blood. This spell had only been used by two known wizards, including:
  • Harry Potter, in 1997, on Draco Malfoy, causing the latter to nearly bleed to death and the former later tried to use it on both the Inferi (which are bloodless) and Snape (who blocked the curse).
  • Snape, in 1997, on George Weasley. Though meaning to strike down a Death Eater, Snape accidentally severed George's ear off, during the Battle of the Seven Potters.
• The Blood-Replenishing Potion replenished blood lost during an injury.
• Vampires were dark magical beings that were known to drink blood as their diet, that belonged to the Living Dead. Some are known as blood brothers. Lady Carmilla Sanguina was a vampire who took things a step further and bathed in the blood of her victims, believing it would help her retain her health and beauty.
• Eldred Worple wrote a book known as Blood Brothers: My Life Amongst the Vampires.

Blood-flavoured lollipops

• Honeydukes sold blood-flavoured lollipops, supposedly for vampires.
• Dolores Umbridge created and owned a quill that scarred whatever one wrote into one's Flesh, as a dark magical torture device.
  • In his fifth year, Harry was scarred by Umbridge's Blood Quill.
• Sometime into the 11th century, the Baron became known as the "Bloody Baron", in the afterlife as a ghost, after he killed Helena Ravenclaw and became covered in her blood.

Quirrell drinking Unicorn's blood for Lord Voldemort in 1991

• In his first year at Hogwarts School of Witchcraft and Wizardry, Harry caught Quirinus Quirrell illegally killing unicorns and drinking their blood for Lord Voldemort.
• In 1992, Rubeus Hagrid thought that a Blood-Sucking Bugbear was killing his roosters, which had actually been killed by Ginny Weasley, being possessed by the fragmented soul of Tom Riddle.
• In 1995, the blood of Harry Potter helped in the Return of the Dark Lord.
• Voldemort's death, in 1998, was mostly because of Harry's blood in the Dark Lord's veins, making him unable to kill the young wizard.

Behind the scenes

• One of the chapters in Harry Potter and the Goblet of Fire is titled "Flesh, Blood and Bone".
• The title of the sixth Harry Potter book, film, video game, and soundtrack is Harry Potter and the Half-Blood Prince.
• During the Battle of the Astronomy Tower, the Gryffindor house point hourglass was shattered by a curse, causing red rubies to flood the floor like blood.

Appearances

• Harry Potter and the Philosopher's Stone (First appearance)
• Harry Potter and the Philosopher's Stone (film)
• Harry Potter and the Chamber of Secrets
• Harry Potter and the Chamber of Secrets (film)
• Harry Potter and the Prisoner of Azkaban
• Harry Potter and the Prisoner of Azkaban (film)
• 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 (film)
• 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
• Harry Potter and the Deathly Hallows: Part 1
• Harry Potter and the Deathly Hallows: Part 1 (video game)
• Harry Potter and the Deathly Hallows: Part 2
• Harry Potter and the Cursed Child
• Harry Potter and the Cursed Child (play)
• Fantastic Beasts and Where to Find Them: The Original Screenplay
• Fantastic Beasts and Where to Find Them (film)
• Fantastic Beasts: The Crimes of Grindelwald - The Original Screenplay
• Fantastic Beasts: The Crimes of Grindelwald
• Harry Potter Trading Card Game
• Pottermore
• Wizarding World (Mentioned only)
• Harry Potter: Hogwarts Mystery (Mentioned only)
• Harry Potter: Wizards Unite