The vampire lore of the Gypsies of Romania tells of a VAMPIRIC WITCH called a ruvaush. Aside from having the ability to create more of its own kind through magic, it can also shape-shift into a wolf, but one that is much larger than a normal wolf. Grevase of Tilbury (1150–1228), a medieval chronicler, was the first person to associate the transformation of werewolves to the moon and its cycles, but his concept was never popular until it was used by modern fiction writers.

Source: Icon Group International, Victims: Webster’s Quotations, 489; Summers, Vampire in Lore and Legend, 92