What we know about the White Walkers took a big step forward in Oathkeeper

White Walker by Elderscroller

Last night's episode of HBO's Game of Thrones was called "Oathkeeper" presumably titled thus because Brienne gave this name to the Valyrian steel blade gifted to her by Jaime Lannister. But the symbolism behind "Oathkeeper" is more vast than a solemn vow made between a knight and her lord. It is about the vows that bind those who have honor and choose to live in the world of Westeros. Everyone has oaths from the Red Viper of Dorne to those who swear fealty to House Targaryen. There's the oath that Jaime Lannister swore to Katelyn, the oaths that the Night's Watch takes to guard the southern kingdoms from the Wildling threat, and now we've seen a different kind of oath. It's one that gives us a glimpse behind the winter curtain of the North and into the society of the White Walkers by answering the question: "What are the Others doing with Craster's baby boys?"

Rumors and speculation over the fate of these babies has been online for years now. George R.R. Martin has never answered any of it in his books, presumably because he thought that he would get to answering certain questions before HBO caught up with him. But it's absolutely apparent from this episode that HBO's makers have been given license to cover material that Martin has not explained. And one of the BIGGEST questions is the fate of these children. Were the White Walkers eating them? Or did they need baby boys to reproduce?

But even with the answer from last night's episode, what do we know about the White Walkers really? Sifting through the novels and my own memory, I present to you my findings.
Called "the Others" in the book, Old Nan (the storyteller who knitted in Bran Stark's room following the accident that left him paralyzed) said, "In that darkness the White Walkers came for the first time. They swept through cities and kingdoms, riding their dead horses, hunting with their packs of pale spiders big as hounds."

The Others, a.k.a. the White Walkers are "mythologicals" in the world of Westeros (mythologicals meaning they occupy the same area of magic and power as dragons). Stories from the time of the First Men and the Children of the Forest, eight thousand years before Robert Baratheon's rebellion, was a winter known as the Long Night that lasted an entire generation. During that winter, the White Walkers descended upon Westeros from the Lands of Always Winter. None knew why they came, they killed everything in their path, and reanimated the dead as wights (under their command) to kill the living. In a conflict known as the War for the Dawn, the White Walkers were defeated and driven back, and the Wall was raised to bar their return.

We know they are humanoid in appearance and now we know why. From "Oathkeeper" the White Walkers (at the end) are seen transforming a baby boy into a baby White Walker in the middle of a cairn that looked a lot like Stonehenge (only made of ice). They are tall, have long wispy white hair, pale white skin that's stretched taut across their frames lending them a gaunt and mummified appearance, and they have glowing blue eyes. Could this be the Night's King? HBO Go briefly labeled this character (with an obvious crown) as such before they took it down. Here's what the wiki for a Song of Ice and Fire has to say about this character:

"According to legend, the Night's King lived during the Age of Heroes, not long after the Wall was complete. He was a fearless warrior, who was named the thirteenth Lord Commander of the Night's Watch. Later he fell in love with a woman "with skin as white as the moon and eyes like blue stars", he chased her and loved her though "her skin was cold as ice", and when he gave his seed to her he gave his soul as well.^[1] (Her description matches that of the Others.)

"He brought her back to the Nightfort and after the unholy union, he declared himself king and her his queen, and ruled the Nightfort as his own castle for thirteen years. During the dark years of his reign, horrific atrocities were committed, of which tales are still told in the North. It was not until his own brother, the King in the North, and Joramun, the King-Beyond-the-Wall, joined forces that the Night's King was brought down and the Night's Watch freed. After his fall, when it was discovered that he had been sacrificing to the Others (possibly in similar way to Craster), all records of him were destroyed and his very name was forbidden.^[1] It is likely this led the lords of the North to forbid the Night's Watch to construct walls at their keeps, ensuring the keeps would always be accessible from the south."

It should be noted that the Others are preceded by intense cold, bitter winds, and snow. They can freeze anything they touch to the point that even steel shatters (although Valyrian steel will probably resist them). They have superhuman strength, and they wield swords and spears made from ice. They also have their own language (Skroth), and it would appear that a touch to the face of a baby creates a "mini-me" version of themselves. Although why they need only babies (and human ones at that) remains unclear. Children even a few years old are not turned but instead slaughtered and made into wights to serve them, so there's something unique about newborns. What that could be is anyone's guess.

They also can be instantly killed by weapons made of dragonglass. According to the red priestess Melisandre of Asshai, the Others are the servants of a deity called the Great Other, the god of darkness, ice and death, who is locked in eternal warfare with R'hllor (the god that Melisandre worships). R'hllor is the god of light, fire, and life. We heard her speak of this God of Darkness this season so color me intrigued. But even with what we know about the White Walkers, there remains these questions:

1) Why are they so hateful?
2) If they are servants of the Great Other as Melisandre suggests, then what are the Great Other's goals?
3) If they need human babies to reproduce, then why do they slaughter humans?