Kreismesser

The Kreismesser, a large iron knife with a rounded tip, is a 19th century exorcism knife. This is the only known example in Europe.
In the magico-religious practices of the Jewish community, it was used in the so-called "circle ceremony" during childbirth. To ward off evil spirits and all malignant influences, the knife was used to describe circles around the head of the mother and the newborn child. Metal was thought to have the property of warding off harmful forces. It bears an inscription in Hebrew characters signifying "You will not let a witch live".
In the past, birth was a dangerous event and death was common for both the woman in labour and the newborn infant. In Jewish communities in particular, the death of infants was readily attributed to the harmful action of Lilith, Adam's first wife, believed to abduct infants unprotected by amulets or rituals.
The legend of the Dockele was particularly widespread throughout Alsace. This evil little goblin was believed to crouch on children's bodies, siphoning off their vital fluids like a vampire or even sometimes suffocating them. This myth is familiar throughout Europe and gave its name to the bad dream in various forms of speech: in Alsatian, Àlbtroem; in German, Albtraum ("elf dream"); in English, nightmare ("night goblin") and in French, cauchemar ("incubus").