Shrunken heads are exactly what they sound like. The practice has only been seen in a few tribes in the northwest region of the Amazon rainforest, but they have become well-known around the world. They were created after someone was defeated in battle; the loser had their head shrunken and sewn shut to keep their spirit inside, which prevented revenge on the killer later on.
To create a shrunken head, the skull is removed from the inside of the skin and boiled before hot rocks and sand are used to dry it. The eyes and lips are sewn shut to capture the spirit inside. It was also believed that rubbing ash on the skin would help this as well.
When shrunken heads became more popular in the mid 20th century, many people started to make fakes using animal heads or skins. Today it is very hard to find a real one, even in museums. There is, however, a real one at the Mutter Museum in Philadelphia which we got to see.