Jötunn

Jötunn (plural form is jötnar), sometimes referred as jotuns, are a chaotic group of creatures that exist in Norse mythology. They live in Jotunheim, one of the nine worlds of the mythos.

Jötnar are counterparts to Aesir, gods of Norse mythology. They're creatures that share bloodline to primordial being Ymir, having been born from his sweat. Jötnar predate all of the Aesir and some, like Odin, are descendants of jötnar.

Overview
It is commonplace to use the word jötunn as a synonym for a giant, which is inaccurate. Jötnar are a broad category of different entities that can range from animals to human-like creatures, from human-sized to enormous, from excruciatingly beautiful to utterly hideous.

While Aesir are often more powerful than a singular jötunn, the distinction isn't all that substantial, and jötnar are far more numerous than Aesir. However, capricious nature of the jötnar is what prevents them from taking coordinated action. That is, until Ragnarök, which is the ultimate battle between Aesir and jötnar and destined to end the world.

Jötnar are not inherently evil, though definitely evil members exist and good jötnar don't seem to exist. They are entropic by nature and often wreak havoc wherever they go, and Aesir often come to blows with them. However, their actions can have a weak sense of purpose, as they can result from childlike, destructive curiosity.

Origins
Primordial being Ymir secreted first two jötnar from his armpits and a third, six headed creature from the soles of his feet. Their kin reigned over the cold and dark realm known as Niflheimr until the Odin and his brothers killed Ymir and flooded Niflheimr with his blood in an attempt to put an end to growth of jötnar.

Odin didn't succeed, but nearly all of jötnar were killed in the process. One or two remained, which was enough for them to start their race anew. The Allfather found it appropriate to banish them to live in Jotunheim.

There were also another breed of jötnar that were said to live in Muspelheim, land of fire. Their interaction in Norse cosmology seems to be sparse. They were involved in the creation of the world, and will take part in destroying it. In the meantime their role is minor.

Named jötnar

 * Fenrir
 * Hel
 * Jörmungand
 * Níðhöggr
 * Þjazi (Thjazi)
 * Skrymir