Disturbing simulation reveals exactly how shrunken heads were made

A harrowing simulation has revealed the lengthy process involved in making 'shrunken' human heads.

A shrunken head is a severed, real human head that indigenous tribes across the world and throughout the ages of civilization.

The practice of headhunting has been documented from a region in the Amazon rainforest and from various peoples in Ecuador and Peru, as either part of a ritual, trophy, trade or other purpose.

An ancient shrunken head in Ecuador (Getty Images)

The terrifyingly distorted heads are, as the name suggests, shrunken in size from when they were once attached to a blood-and-flesh body, having been specially prepared using a specific process to decrease the size.

Now, a simulation has been made which reveals the disturbing extent of the process of making such heads.

The YouTube video, created by Zack D. Films, explains how warriors would 'first remove the skull and skin from a defeated enemy's head'.

Once successfully decapitated, the warrior would make an incision at the back of the ear and remove flesh from the cranium.

The process involved sewing the eyes and the mouth shut (YouTube/Zack D. Films)

The simulation reveals the triumphant warrior would then painstakingly sew the eyes and the mouth of their victim shut, 'to prevent the enemy's spirt from seeking revenge'.

The shrinking process was originally steeped in religious significance, as it was believed the soul of the dead could 'seep' out of the head and avenge their killer.

The next stage of the process involved boiling the head to preserve the skin, as demonstrated by the simulation.

Other sources claim a wooden ball was also used to retain the form of the head.

The head was then boiled to shrink it (YouTube/Zack D. Films)

This unsettling stage was vital as it shrunk the head's size while keeping all the facial features intact, the simulation explains.

Then finally, the significantly smaller head was filled with hot stones and sand, which served to shrink it even more.

The educational simulation video says the heads were then worn as trophies or were used in rituals 'for protection and power'.

Fans of the YouTube channel have since weighed in on the simulation, which landed Christmas Day, writing that Zack 'never disappoints'.

One user wrote his content 'never fails to traumatise, never runs out of ideas' and said the animators 'need a raise'.

Another fan added: "Even Christmas can't save me from his nightmarish animation," while others joked 'merry Christmas' and said they were glad to have tuned in to this particular 'tutorial'.

"Wearing your enemy's head as a trophy is wild," another penned.