At first glance, the giants of Morus seem to have very little culture. All of them are physically imposing. Some, like the hill and stone giants, have little more than the rudest tribal society. Others, like frost, fire and cloud giants, have various levels of sophistication. But even so, a common thread that binds them all together is not easily seen. Yet nonetheless it exists.
The wellspring of gigantine culture starts in a very unexpected place - the linnorms. As documented in the history of divinity on Morus, linnorms are the primeval dragons. They first appeared in the very beginning, when Morus was first bounded. The strange and eldritch beings known as the Ancient Masters were bounded with Morus, and so the linnorms came to be. This story is not restricted to Morus, however - the Ancient Masters are the manifestation of primal unchanging forces throughout the planes, and wherever a material plane is bounded, linnorms come to be. This is why linnorms can be found in all shapes and sizes, and in every world. Some are even famous across many worlds, such as Corpse-Tearer or the Midgard Serpent.
Children of Linnorms
While linnorms are called primeval dragons, this is perhaps misleading. While dragons are powerful, noble, intelligent beings in their own right, they are in truth a corruption and imperfection of the linnorm. The linnorms are, in turn, a corruption of the so-called Ancient Masters. These beings were simply spirits, powerful and infinite spirits, that existed in a time before time. They represented the power of inertia, the massive and implacable unchangability of the multiverse, and they resist all attempts at change and progression. They were eternal and immortal in the truest of senses, unchanging and unchangeable.
When the world was bounded, however, the Ancient Masters became linnorms; though still immortal they were bounded and finite. They had changed - and become agents of change - and their very nature rails against this change. So they seek always to destroy the very firmament that caused them to be, and their only desire is to return to the hazy infinity that existed before the world was born. With their finite nature and the diminishing associated with it, they ceased to be natural forces and became creatures, no more. These creatures bore children beyond them, and so a line was forged.
When linnorms mated with each other, other linnorms were sometimes created. However, the potency of the primeval dragons is such that the line was bound to fail and diminish with time. As the generations have passed, the linnorms that still survive are few - they have been superceded by their lesser progeny, which is dragonkind. In this way, every dragon is the direct descendant of their ancient ancestors. And therefore, each dragon is descended from the forces that precipitated the creation of the world.
When the linnorms mated with gods, the jotunn were formed. The Aesir of the Norse are the most well known for doing this, and they are thought to be the originators of giants throughout the planes. Jotunn are neither demigods (as the Aesir are), nor are they linnorms - but they have elements of each. Like the linnorms, they have a variety of shapes and sizes - they are not giants, though the Norse often use the word to refer to giantkind. The Midgard Serpent, for example, is the child of Loki - and none are sure exactly whether it is a linnorm or a jotunn. Likewise, Fenrir is a jotunn even though he takes the shape of a great wolf.
The jotunn draw elements from both of their parents. Just as linnorms represent the elemental forces of creation, so too do the jotunn. This is how it comes to pass that there are fire jotunn, and there are ice jotunn. Like the gods, they can aspire to great ambitions and high ideals, and they can marshal great wisdom, craftiness and powerful sorcery towards their ends. The linnorm blood in them makes them primal creatures of elemental fury, however - a dangerous combination indeed. Although there are jotunn everywhere and from many different origins, they are renowned for dwelling in Niflheim, realm of the ice jotunn, and Muspelheim, realm of the fire jotunn, where they are ruled by Bergelmir and Surtr, respectively. Niflheim is located in the Grey Waste, while Muspelheim is located on the second layer of Ysgard.
The jotunn are powerful, but like the linnorms, breeding together diminishes the divine blood in their line and produces a line of mortal progeny after them. These are the beings we now know as giants. Some giants, such as those found in Muspelheim, Niflheim, or the extreme north of Morus, know of their heritage and live amongst the jotunn. Others live a life in ignorance, or have garbled and contradictory teachings that have been passed down only through oral traditions over the centuries. The giants of Leng fall into the latter category.