Trocar

Trocar was a vampire, and a teacher at Hogwarts School of Witchcraft and Wizardry.

Behind the scenes

 * Trocar made an appearance only on J. K. Rowling's earliest planning notes for the books, and disappeared from her plans fairly early on, since she "did not think much of him as a character".
 * A trocar is a medical device inserted into arteries or cavities to extract bodily fluids.

Appearances

 * Pottermore