by Ben McSweeney
The koloss are a bestial race of creatures on Scadrial, created by the Lord Ruler through the use of Hemalurgy. During the time of the Lord Ruler, koloss serve as a powerful, fiercely loyal army to him, thanks in no small part to the fact that they can be controlled through the use of Allomancy by any powerful Mistborn or group of brass mistings. .
The koloss are physically very large and very powerful. Koloss have blue skin and red eyes.  A full-sized koloss could grow to be as tall as twelve feet. A young koloss has as much skin as it would come to have in its later life. Because of this, the younger a koloss is, the fatter it appears, due to having so much baggy skin covering itself. The skin itself doesn't hold terribly firmly to the koloss' body. As the koloss grow taller, their skin tears and fits tightly to them. An ancient koloss will have little to no skin at all, being covered instead in leather wrappings.. When a koloss reaches about twelve feet, its heart can no longer sustain its body, and it dies shortly thereafter.
Creation and reproduction
Similar to Steel Inquisitors, the creation of a koloss is very brutal. To create a koloss, four humans are stabbed with individual iron spikes through their heart, and these spikes are then placed strategically on to a fifth person. Once placed, the spikes turn the recipient into a koloss "very quickly".
The addition of four spikes containing the strength and a portion of the spiritweb of four other people causes them to grow in physical strength far beyond human limits as well as making it possible for them to continue growing in size until they can no longer physically support their own bodies and their hearts give out. The four spikes also have the effect of reducing their intelligence to almost that of a basic animal. These spikes can be reused, however, they are subject to Hemalurgic decay, meaning that the power in the spikes diminishes with each re-use, which allows for more of the koloss' humanity to remain.
When a koloss dies, other koloss in the vicinity attempt to collect and reuse the spikes from the dead one. This results in the koloss being able to reproduce in a manner of speaking, provided that they have someone to receive the spikes. The koloss are periodically supplied with fresh spikes and skaa captives to produce more koloss, but after the death of the Lord Ruler, they learned how to reproduce on their own; by harvesting the spikes from their dead brethren and re-using them.
Because of this, after the Lord Ruler's control over the koloss ends, many of the koloss attack nearby human inhabitants in an attempt to make more Koloss. When Vin visits a Koloss camp, they request for her to give them more Koloss. She does not know how, but they expect a human to be able to provide them with more Koloss, since that is what they have experienced in the past.
In the post-Catacendre era, Koloss became a self-reproducing species. When two koloss reproduce, the offspring are born koloss-blooded. This means that they are physically strong, with a mottled granite-like complexion. A semi-offensive term for them is "kig". Furthermore they continue to grow taller throughout their lives. They heal quickly and are often less intelligent than average. They become a full koloss once they accept the spikes. Wax estimates Tarson to be young purely by his short but stocky frame.
The only real powers in a koloss' arsenal are superhuman strength and increased size. However, this comes at a price. Koloss in the Final Empire are nowhere near as intelligent as they were as humans. However, they still retain the faint ability to reason, and the ability to communicate, and the re-use of spikes from dead koloss to create more resulted in koloss that retained more of their former humanity.
Allomancers who are transformed into koloss will retain their Allomantic abilities, though they may not necessarily retain the knowledge to use those abilities.
Because of their diminished intelligence, the Final Empire-era koloss live in barbaric tribes. Usually, social standing is determined by age, because as the koloss age, they get larger and more powerful.
Koloss are said to have two emotional states: boredom and rage. Because of this, their day to day lives are filled with milling about and fighting. When there is nothing else to fight near them, the koloss turn to in-fighting. Their blades are distributed as a means of population control, as well as weaponry. If a koloss doesn't have a sword, it will have to kill another koloss and take its sword. If there is an extra, they can make a human into a koloss.
Most of the killing within a tribe is done solely on a whim, usually to get something the other koloss owns, or because some random glance or act has enraged one of the koloss.
After the Ascension
After Harmony's Ascension, however, the koloss were transformed into a tribal race that could breed, which lived in the Roughs. As a true breeding race, Koloss raise koloss-blooded children. Those who chose can turn into full koloss at the age of twelve in a coming-of-age ritual where they choose to accept the requisite spikes or not. Those who do not accept the spikes leave, and live outside the tribe. Additionally, outsiders can choose to become koloss through this ritual.
The changes in the Koloss and their breeding subsequently allowed some koloss-blooded to become allomancers. How this is achieved is unknown, but Koloss with the powers of allomancy appear to be known in the Roughs enough to be recognized. 
Since the Koloss are no longer required to fight for anybody, they are able to live longer lives. This allows for the development of Koloss ancients, who have little to no skin at all. They are enormous, have no noses or lips, and their eyes appear to bulge. They survive only by wrapping themselves in leather to keep in their blood. While their intelligence is still at the level of the average Koloss, they are looked after by the tribe and given respect similar to that of a tribal elder .
- The Hero of Ages chapter 37 #
- The Hero of Ages chapter 40 #
- The Well of Ascension chapter 54 #
- The Hero of Ages chapter 3 #
- The Hero of Ages chapter 21 epigraph #
- The Well of Ascension chapter 19 #
- Allomancer Jak and the Pits of Eltania #
- General Signed Books 2015
— Arcanum - 2015-01-01#
- The Hero of Ages chapter 40 epigraph #
- The Hero of Ages chapter 42 epigraph #
- The Alloy of Law chapter 5 #
- The Bands of Mourning #
- Words of Radiance Portland signing
— Arcanum - 2014-03-07#
- The Alloy of Law chapter 19 #
- 17th Shard Interview
— Arcanum - 2010-10-03#
- Orem signing 2014
— Arcanum - 2014-12-06#
- The Alloy of Law chapter 6 #
- The Alloy of Law chapter 11 #
|The Metallic Arts|
|Arts||Allomancy · Feruchemy · Hemalurgy|
|Concepts||Metalborn · Snapping · Savants · Metalminds · Twinborn · Compounding · Blessings|
|Constructs||Steel Inquisitors · Koloss · Kandra · Chimeras|
|Base Metals||Iron · Steel · Tin · Pewter · Zinc · Brass · Copper · Bronze · Cadmium · Bendalloy · Gold · Electrum · Chromium · Nicrosil · Aluminum · Duralumin|
|God Metals||Atium (Malatium) · Lerasium · Ettmetal · Trellium|
|Era 1 books||Mistborn: The Final Empire · The Well of Ascension · The Hero of Ages · (Mistborn: Secret History · The Eleventh Metal)|
|Era 2 books||The Alloy of Law · Shadows of Self · The Bands of Mourning · The Lost Metal · (Allomancer Jak and the Pits of Eltania)|
|Shards||Preservation · Ruin · Harmony|
|History||Classical Scadrial · Final Empire · Catacendre · Elendel · Southern Scadrian|
|Magic||Metallic Arts (Allomancy, Feruchemy, Hemalurgy) · Metalborn · Mistborn · Misting · Savant · Ferring · Twinborn · Compounding · Atium · Lerasium · Ettmetal|
|Other Media||Mistborn Adventure Game · Mistborn: Birthright · Mistborn film · Mistborn: House War|