Q-Negative

Q-Negative was an exotic, moderately-rare "universal donor" blood type displayed by some humanoid species, including the people of Hoppiq Minor. It was favoured by the vampire king Zadok, leading Miss Garglespike to stockpile a large stash of the stuff as part of her failed assassination plot against Zadok. One of the people she drew the blood from was Venn. (PROSE: The Bloodletters)