This film apparently was a Spanish attempt to cash in on the success of The Exorcist, which came out the year before. To sum up the cliche'd plot, a cult of Satanic gypsies kidnaps a little baby boy, and the police arrest an old gypsie witch that they suspect has the child. The witch jumps out of a window to her death, but manages to possess the police chief's teenage daughter. The girl starts getting a foul mouth on her, and later transforms into a teenager version of the old witch and sacrifices the missing baby to Satan and then proceeds to kill a few more people for good measure. After the little witch tries to kidnap her baby cousin to sacrifice, finally a priest tries to exorcise her leading to the rather pointless ending.
Overall, the movie was very slow and had little originality to offer. The violence wasn't particularly gory or graphic and there aren't many special effects to speak of. The only good thing I can say for this movie is that they did a good job of making the transformed version of the young girl look a lot like the old witch.