Shrunken Head, Jivaro Indian, Ecuador. Although there were many headhunting cultures throughout the world, only one group was known for ancient practice of shrinking human heads (tsantsa or tzantza). They were called the Shuar (mainly), Achuar, Huambisa and Aguaruna, collectively classified as the Jivaroan peoples of Ecuadorian and Peruvian Amazon rainforest. The Jivaros are one of the most primitive societies that have caught the attention of the Western world because of their unusual customs. The Jivaros are the only tribe known to have successfully revolted against the Spanish Empire and to have been able to thwart all subsequent attempts by the Spaniards to conquer them. A shrunken head is a severed and specially prepared human head that is used for trophy, ritual, or trade purposes.