A Samca is a creature in Romanian Legends as an ugly and terrible evil spirit. She can take many different forms like a large pig, a grinning dog with rotten teeth, a hairless cat with fiery bulging eyes, a crow with bloody eyes, and a large black spider. The most known version is of a naked woman with disheveled hair down to her feet, dried out breasts that touch the ground, small bright eyes, a tongue of fire, and iron hands with nails as sharp as knitting needles or hooked as sickles.
They show themselves at the end of the month usually around the full moon. With their large crooked mouth, they show in front of children under 4-years-old. A disease that children get after the Samca appeared often called "the children's malice". This causes the child to be deathly ill.
They also show themselves to women lying on their birth bed, and once the creatures are visible they touch the pregnant woman as if kneading them. This would either scare the women to death or cripple them for life. It's also said that the Samca would curse the newborns.
Samca goes by 19 names; Vestitia, Navadaria, Valnomia, Sina, Nicosda, Avezuha, Scorcoila, Tiha, Miha, Grompa, Slalo, Necauza, Hatavu, Hulila, Huva, Ghiana, Gluviana, Prava, and Samca. In order to avoid the Samca people would need to write all 19 names on the wall of the house or ask someone for a protective spell. If attacked the person who did the spell gets attacked, except if the person is of age the Samca cannot.
SOURCES:
Wikipedia
Monster Wiki
Right Words
Librum Prodigiosum (tumblr)