Crucifix
From Tardis Wiki, the free Doctor Who reference
In mythology, vampires feared crucifixes. However, in the case of the Haemovores, they were not afraid of the object itself, rather the faith of people who carried them. (TV: The Curse of Fenric)
H. G. Wells in 1885, mistaking the Sixth Doctor who had just arrived to be a spirit, attempted to hold up a crucifix, along with a Bible, to repel him. (TV: Timelash)