The cabeça Satânica or Satanic Head is a Brazilian ghost that is, as the name implies, only a head. Also known as the Wandering Head, the origin of this myth is unknown, but is likely based on Portuguese legends.

The Satanic Head is described as having long, stringy black hair, glowing red eyes, and a high pitched tittering laugh. It often drops down on the back of an unsuspecting victim or bounces around as if dancing. In some cases the head is carried by a headless ghost that throws the laughing skull at a victim and then disappears (c.f. Dullahan). Other times it appears to be a whole individual dropping from above, but while the body continues to drop and fall to the ground, the head remains floating in space.

The touch of a Satanic Head is said to cause sickness and eventually death, but the evil spirit doesn’t otherwise harm a victim. It seems to enjoy causing fear and panic. There doesn’t seem to be a specific reason for the head to attack someone, other than opportunity. No one knows what creates the head, nor who it may have been in life, so there’s no specific connection to its victims.

Wikipedia – Brazilian Mythology – 10 Creatures of Brazilian Folklore You Don’t Want to Meet
Sinister Night – Legend of the Satanic Head