Mormont's Raven Is The Three-Eyed Crow

This is a theory I thought up while answering a question from one of u/Financial_Library418's posts on r/asoiaf. Reasearch led me to this theory that predates my own: ( Spoilers EXTENDED ) Crackpot Theory : Bran is the Three Eyed Crow and he is warging into Mormont's Raven from the future, trying to warn Jon about the Horn of Winter : r/asoiaf

Many analysts question the conclusion that Brynden Rivers is the three-eyed crow. Bran questions it and I believe readers are meant to.

""Are you the three-eyed crow?" Bran heard himself say. A three-eyed crow should have three eyes. He has only one, and that one red. Bran could feel the eye staring at him, shinning like a pool of blood in the torchlight. Where his other eye should have been, a thin white root grew from an empty socket, down his cheek, and into his beck. "A...crow?" The pale lord's voice was dry. His lips moved slowly, as if they had forgotten how to form words. "Once, aye. Black of garb and black of blood.""

The three-eyed crow is the "person" who contacted Bran in his coma in A Game of Thrones, showing him a vision of The Others and helping him to wake. This dream crow later opens Bran's third eye. Then, Jojen explains that he and Meera were sent by this three-eyed crow to help Bran to seek his teacher beyond the Wall. Some believe the crow is Bran from the future. I believe the crow is a warg dimming in his second life inside Mormont's raven.

Reason #1: Sub-theory: Lord Mormont's Raven is Warged

This popular theory is rooted in observations that even Mormont does not know where the raven came from and that the bird's immediate affinity for Jon Snow--even having decided the election with a stunt--suggests he's been "the Lord Commander's raven" for generations preceding.

My take on this theory is that it is obvious a warg among the wildlings would have the ability and incentive to infiltrate the Night's Watch for information as a warged raven. That the Lord Commander has a raven suggests that raven is a spy. However, we not only do not meet this warg in Mance Rayder's camp, Lord Mormont's raven seems way too interested in corn to still be alive as a warg. From what we learn in the Varamyr Prologue, it seems plausible the sentience that moves Lord Mormont's raven to meddle has dwindled because this is only a warg in his second life: a man becoming daily more interested in corn.

Reason #2: Corn

The voice was high and thin. Bran looked around to see where it was coming from. A crow was spiraling down with him, just out of reach, following him as he fell. "Help me," he said.

I'm trying, the crow replied. Say, got any corn?

Bran reached into his pocket as the darkness spun dizzily around him. When he pulled his hand out, golden kernels slid from between his fingers into the air. They fell with him.

- A Game of Thrones - Bran III

When Bran climbed the broken tower in Bran II, he filled his pockets with corn, as always, to feed to the crows that lined the battlements. That the crow of Bran's dream is interested in corn could be read to suggest that the three-eyed crow personality is a delusion resulting from the trauma of his fall and coma: a true dream crow.

Another explanation is that Bran was indeed contacted and guided by a person beyond the Wall in order to reach his teacher, Brynden Rivers. However, the teacher seems to be someone else. It might be that that person, who talks a lot about corn and who we see act as a major meddler was always Lord Mormont's raven. Both are introduced here:

Jeor Mormont, Lord Commander of the Night's Watch, was a gruff old man with an immense bald head and a shaggy grey beard. He had a raven on his arm, and he was feeding it kernels of corn. "I am told you can read." He shook the raven off, and it flapped its wings and flew to the window, where it sat watching as Mormont drew a roll of paper from his belt and handed it to Jon. "Corn," it muttered in a raucous voice. "Corn, corn." - A Game of Thrones - Jon III

When he entered the solar, Mormont's raven screamed at him. "Corn!" the bird shrieked. "Corn! Corn! Corn!"

"Don't you believe it, I just fed him," the Old Bear growled. - A Game of Thrones - Jon VII

Mormont's Raven is so associated with cries of "corn" that it is the word he uses to warn Jon a wight is attacking:

Suddenly he heard the shriek of Mormont's raven. "Corn," the bird was screaming. "Corn, corn, corn, corn, corn, corn." Ghost bounded ahead, and Jon came scrambling after. The door to Mormont's solar was wide open. The direwolf plunged through. Jon stopped in the doorway, blade in hand, giving his eyes a moment to adjust. Heavy drapes had been pulled across the windows, and the darkness was black as ink. "Who's there?" he called out.

Then he saw it, a shadow in the shadows, sliding toward the inner door that led to Mormont's sleeping cell, a man-shape all in black, cloaked and hooded … but beneath the hood, its eyes shone with an icy blue radiance … - A Game of Thrones - Jon VII

Reason #3: The Disappointment is Total

Readers are comforted by the idea it was an ancient wizard, Brynden Rivers, who reached out telepathically to Bran in his crisis and awakened his greenseer abilities. This conclusion is reasurring because it suggests the sentience guiding Bran is knowledgeable, experienced, right and competent. Yet, the wise man Bran meets is so blended with the weirwood network that his identity is dwindling. I outline, in Why didn't the Three Eyed Raven have Benjen Stark bring Mance Rayder and his army of Wildlings to his tree to keep them safe from the Night King and his army of the Dead? - A Space of Ice and Fire - Quora why Brynden Rivers no longer sees political and military situations as his concern.

It is a short leap from the disappointment Bran feels at being guided to a teacher who cannot give him back his legs to the disappointment of realizing he was guided beyond the wall by someone well-meaning but not all-knowing or able to do much more than he did by waking Bran up and opening his third eye. While Brynden Rivers and the Children of the Forest guide Bran into the weirwood web, this does not seem like the final seat of a spirit depicted as a winged wolf. Bran still must fly, unless what the three-eyed crow always meant was for Bran to warg crows?

If Lord Mormont's raven is the three-eyed crow, it suggests we'll see him do as much or more in The Winds of Winter as he has in previous books. That could be exciting but--unless he comes to be warged by some other sentience like Jon or Bran or some wildling-- it is likely his days of high intelligence are gone and that he is only the memory of a great man.