Drogon

"Dracarys!"

- Daenerys Targaryen telling Drogon to breathe fire.

Drogon is one of the three dragons born in the Dothraki Sea, along with Rhaegal and Viserion. He is named after Daenerys's late husband Khal Drogo. He can be distinguished by his black and red colored scales, and red-black wings. He is also Daenerys's personal mount.

Season 1
He is born along with his two siblings after Daenerys has their eggs placed on the funeral pyre erected for her deceased husband, Khal Drogo. As she rises unharmed from the ashes of the pyre on the morning following the funeral, he climbs on her shoulder and lets out a powerful scream, announcing the return of dragons to the world.

Season 2
As her small khalasar travels east, Daenerys tries to get Drogon to eat, but he refuses the raw meat she offers, just as his siblings do. Later, while Daenerys is staying at Qarth, she teaches Drogon to breathe fire for the first time, roasting a small piece of meat, which he then eats. Drogon and his siblings are kidnapped to the dismay of Daenerys. In a meeting with the Thirteen, Pyat Pree, a warlock, reveals he has taken them to the House of the Undying and claims that he is eager to reunite Daenerys with her children.

After Daenerys enters the House of the Undying, she eventually finds her three dragons chained to a small dais. Pyat Pree suddenly appears and chains Daenerys with magic, saying that her dragons make his magic strong, that she makes the dragons stronger, and thus she must stay in the House of the Undying forever.

An unconcerned Daenerys whispers "dracarys" to Drogon, and after a couple of tries, he spits a large plume of fire at Pyat, igniting the warlock's robes. The other two dragons follow their brother's lead and the three of them burn Pyat Pree alive, free themselves and Daenerys from their chains, and set the House of the Undying alight.

Season 3
Drogon has grown significantly since leaving Qarth, and is about the size of a small dog by the time Daenerys and her party reach Astapor. He swoops into the water and catches a fish, which he then cooks in mid-air and devours. Daenerys notes that he is not growing fast enough for her to use him to conquer the Seven Kingdoms in the immediate future.

At Slaver's Bay, she speaks with Kraznys mo Nakloz, as they attempt to work out a deal for his slave soldiers, the Unsullied. Daenerys says she will take all eight thousand Unsullied, including those in training. To this Kraznys laughs at her and says even with the wealth she possesses she could afford hardly over one hundred Unsullied. Daenerys surprises him by reminding him she has Dragons, and she will give him one. They strike a deal that she may have all the Unsullied, as well as those still in training, in exchange for her biggest dragon.

Sometime later the exchange is made, and Daenerys meets with the Good Masters and gives the chained Drogon over to Kraznys, who in turn gives her the golden scourge which signifies absolute authority over the Unsullied. Once the Unsullied are under her command, Kraznys angrily comments that Drogon does not obey him, to which she responds, in Valyrian, that he does not obey because dragons are not slaves. Daenerys orders Kraznys's death with a harsh "dracarys". Drogon then takes flight and strafes the guards and Good Masters in the walls above the plaza.

After the Sack of Astapor is finished, Daenerys's khalasar and her new Unsullied army march out of the city, Drogon and his brothers flying overhead.

Drogon and his brothers are present in Daenerys' tent when a Wise Master from Yunkai arrives to entreat with their mother. Drogon, now about the size of a large dog, aggressively barks at the Master when he gets too close to Daenerys. Later, the Wise Master has two slaves place a chest full of gold near Drogon. While the two talk, Daenerys throws a piece of meat to Viserion, and Drogon attempts to steal it from his brother. When the negotiation goes sour, Drogon growls at the Wise Master for threatening Daenerys. Scared for his safety, the Wise Master tells his slaves to take back the gold and leave. Drogon stops them in their tracks, hissing and growling.

Season 4
Drogon and his siblings are now the size of small horses. He quietly rests his head on his mother's lap as she caresses him. When his two siblings come back with a dead lamb, he joins the fight over the carcass. His mother tries to calm him down, and without warning, Drogon snaps at her with a hiss; a warning to not interfere. He then roars and goes to contest the kill. Daenerys is shaken, fearing that she is losing influence over her "children", as dragons can never be truly tamed.

On the run from the Lost Legion, Asher Forrester, his uncle Malcolm Branfield, and partner Beskha encounter Drogon inside a cave, but manage to escape. Asher later reports the find to Daenerys while asking for help, though she does not believe him, even with evidence to support the claim.

Following Daenerys's conquest of Meereen, Drogon, who is now the size of a small ship, kills and eats the goats of a local goatherd. The goatherd lays the charred bones of his flock before Daenerys in her throne room, hoping he has not angered the new queen and that this was a form of punishment. Daenerys apologizes for Drogon's actions and promises to pay the goat herder back three times the worth of his lost goats.

Dany is later dismayed to learn that Drogon has killed the young daughter of another goatherd. She tearfully confines the two smaller dragons to the catacombs of the pyramid while Drogon remains at large, having last been seen over the Black Cliffs.

Season 5
Daenerys confides in Daario Naharis that she has no idea where Drogon has flown off to.

After the public execution of Mossador, Daenerys encounters an even further grown Drogon, who has become the size of a killer whale, on top of the Great Pyramid. She reaches out to him, but Drogon flies away at the last moment.

Drogon apparently flew west, eventually winding up roving the skies above the shattered ruins of the Valyrian Peninsula, where he was glimpsed by Jorah Mormont and Tyrion Lannister, who were traveling through the region to avoid pirates. Massive and majestic, Drogon's unexpected appearance rendered the typically chatty Tyrion speechless and seeing him again also enraptures Jorah. Drogon's flight unfortunately distracted the pair long enough for them to be attacked by Stone Men.

While Daenerys attends the grand re-opening of the fighting pits at the Great Pit of Daznak, a large group of Sons of the Harpy appear and attack her council and the spectators. While trying to escape, Dany and her small group become surrounded by the Sons with no chance of escape. Drogon suddenly appears, flying out of a flame burst and begins to attack, burning the Sons with his fiery breath and crushing them in his massive jaws. Temporarily retreating in terror, the Sons regroup and retaliate by throwing spears at Drogon, wounding him slightly. Dany pulls a spear from Drogon's neck, then climbs on his back to remove another one. She commands him to fly away, and he does so, with Dany on his back.

Later, Drogon lands atop an impressive hill in a sea of green grass. Though Dany tries to convince him to take her back to Meereen, Drogon is still recovering from his wounds and is uninterested in flying back. Daenerys wanders away to find something to eat, but she is quickly surrounded by a Dothraki khalasar.

Season 6
At some point following Daenerys's takeover of the Dothraki, she senses Drogon trailing her. She slips away and rides him around the khalasar before landing and giving a rousing speech while mounted on his back. He is significantly larger than he was during the battle in Meereen. Eventually, Drogon carries Dany to the Great Pyramid of Meereen, which is under siege by the Masters.

Daenerys discusses terms of surrender of the masters in Meereen. The masters foolishly mention slaughtering the dragons, which angers their mother. Drogon suddenly appears, lands next to her, and moves one of his wings allowing her to mount his back. As Drogon takes flight, Viserion and Rhaegal break out of the catacombs and join their brother in the sky at last. At Dany's command of "dracarys", Drogon leads his brothers in immolating the slaver fleet with dragon fire, decisively ending the Second Siege of Meereen.

Some time later, Drogon and his brothers accompany their mother and her large army on a voyage to retake Westeros by soaring above the armada.

Season 7
Drogon and his brothers fly ahead of their mother as she lands on Dragonstone. They investigate the island as Daenerys enters and secures the castle.

Upon Jon Snow's arrival at Dragonstone, Drogon and Viserion fly overhead and visibly scare both him and Davos Seaworth. Tyrion then comments that he has not yet got used to them either.

Later, Daenerys, frustrated at her losses, takes Drogon (along with a massive Dothraki horde) to the Reach in a surprise attack on the Lannister forces. The Lannisters are completely unprepared for a combined assault from Dothraki cavalry and dragonfire at the same time, and are quickly overpowered. At Dany's command, Drogon breathes a massive torrent of fire straight through the Lannister ranks from front to back. The Lannister archers attempt to shoot Daenerys off his back, but he banks up, and the arrows bounce harmlessly off his armored underside.

Suddenly, a massive scorpion bolt whizzes past Drogon, startling Daenerys. She looks down to see the scorpion itself, as Bronn reloads it. Drogon sees it too, and charges across the battlefield, but Bronn fires a second bolt straight into Drogon's shoulder. With a screech of agony he plummets towards the ground in freefall, with Daenerys struggling to hold on. However, although the bolt previously punched through a dragon skull, this time, being fired upwards and from a larger distance, it only manages to inflict a flesh wound on its target; Drogon manages to pull himself together before hitting the ground. He hovers in the air right in front of Bronn, who leaps out of the way as the enraged dragon incinerates the scorpion with his fire. He then lands on the battlefield and roars, demolishing what remains of the scorpion with an angry swipe of his tail.

Daenerys then dismounts and attempts to remove the scorpion bolt embedded in Drogon's shoulder. Despite being superficial, the wound is still painful, and Drogon howls in pain and fury as his mother tries to pull it out. Suddenly, Dany sees Jaime Lannister charging towards her with a spear in his hand, hoping to kill her then and there. Unfortunately for Jaime, Drogon sees him too; shielding Daenerys behind his head, he breathes fire at the charging Jaime, who is saved from certain death when Bronn tackles him off his horse and into the river.

In the aftermath of the battle, Drogon rests on a small hill looking over the surviving Lannister men brought before his mother. Dany offers the remaining men a choice: kneel or die. When most of them refuse, Drogon (as if annoyed by this) roars, frightening many more into bending the knee. After Daenerys' request is denied by Dickon and Randyll, Drogon burns them alive, causing the rest of the surviving soldiers to instantly kneel in fear.

Daenerys' returns to Dragonstone while riding Drogon. Jon watches as they land and remains stoic, even after Drogon roars. Sensing something in Jon, Drogon allows the King in the North to get close enough to pet him; much to the surprise of Dany. After Daenerys dismounts him, Drogon joins his brothers in the skies above Dragonstone. Daenerys remarks how beautiful they are, and though Jon mentions he wouldn't exactly call them that and refers to them as beasts; Daenerys is quick to remind him they are her children.

Drogon, Rhaegal, and Viserion accompany Daenerys beyond the wall to rescue Jon Snow and company beyond the Wall, burning many wights in the process. Viserion is struck in the neck by an icy javelin, courtesy of the Night King, and is brought down, crashing through the frozen lake. Drogon cries out for his dying brother, but can do nothing to help him. Jon is then left behind as Drogon takes to the air, narrowly avoiding a second ice spear from the Night King.

When Daenerys goes to parley with the Lannisters in King's Landing, she rides Drogon to the Dragonpit in a show of force.

Physical appearance and personality
Drogon is noticeably larger than Rhaegal and Viserion. Initially the luck of the draw in terms of biology, Drogon became even larger than them, as they spend months chained beneath Meereen while Drogon remained free. Most of his scales are black, shadowing red ones that run down his back and neck. His wings and frills are black-red mix, down to the wing-bones which are black. His eyes are orange-red. Over the course of the series he has grown considerably, from the size of a kitten in Season 1 to the size of a large whale in Season 7.

Drogon is the least shy of the three dragons when it comes to interacting with humans, albeit for the worst. He is by far the most aggressive of the three, easily agitated and quick to anger, as seen when he is a juvenile and he snarled at a Yunkai Wise Master when he approached his mother. He is also the first to react to orders and takes the initiative in confrontations, as seen when Daenerys ordered her dragons to burn Pyat Pree or when the Wise Master threatened her, he was the first to jump to his mother's defense. He often seeks his mother's affection, and is often seen being caressed by her. However, even she isn't safe from his anger, as seen when he snarled at her without warning when she tried to defuse a conflict between the three. That said, he is fiercely protective of his mother, and will fight viciously in order to defend her, ignoring wounds if needed, as seen when he attacked the Sons of the Harpy in the Pit. It appears that he can sense when Daenerys is in danger, and if he does, he will rush to her aid. His larger size also makes him take a dominant role among his siblings, shown in how easily he stole a lamb from Rhaegal and Viserion; they cease their squabble and instead squeal for him to share the lamb with them.

Despite his flaws, Drogon is shown to care greatly for Rhaegal and Viserion, as he roars in anguish when Viserion is killed by the Night King. 

In the books
In the A Song of Ice and Fire novels, Drogon is much the same. He is the largest and most aggressive of Daenerys's dragons. She named him in memory of her recently deceased husband, Khal Drogo.

Balerion the Black Dread, the dragon of Aegon the Conqueror, was also colored black with red highlights. Generations later, Daenerys Targaryen thinks that her newly hatched dragon Drogon resembles descriptions of Balerion so closely that he is actually a reincarnation of Balerion's spirit, though she gives him a new name for his new life.

When Daenerys enters the House of the Undying, Drogon accompanies her. Once inside, Drogon reacts to the visions that Daenerys has. When they come upon the Undying, Drogon defends Daenerys by attacking the pulsating heart that stands at the center of the room, thereby slaying the Undying. This allows Daenerys to escape the House and seems to have seriously damaged the structure itself.

In the third novel, Daenerys notices that Drogon is more developed than his brothers: he grows faster, is the first to fly above the water, first to flutter from ship to ship, the first to lose himself in a passing cloud, and the first to kill prey. He is always hungry. At one occasion, Rhaegal tries to snatch a piece of meat from him but fails. Drogon also grows more violent than his brothers: he bites Irri's hand when Daenerys is not around. Daenerys apologizes for that.

When the Wise Masters of Yunkai threaten Daenerys, she says "Dracarys" and Drogon burns Grazdan mo Eraz's tokar, who soils his pants in fear. Daenerys taunts Grazdan for whining about the tokar. Grazdan tells angrily, "These little lizards will not keep you safe, I promise you. We will fill the air with arrows if they come within a league of Yunkai. Do you think it is so hard to kill a dragon?" Daenerys answers nonchalantly, "Harder than to kill a slaver."

During the fifth novel, Daenerys is so busy ruling Meereen that she neglects the dragons. Like any wild beast that is left to grow without proper training, all three grow savage and unrestrained, especially Drogon; first they prey on sheep and goats, causing significant losses to shepherds. Only after a little girl is killed by Drogon does Daenerys realize the dragons pose a great danger to her subjects, and must be kept locked in a makeshift dragon pit, large enough to hold 500 men, inside the Great Pyramid.

Viserion and Rhaegal are caught and chained, but Drogon is tougher: three times her servants try to capture him, but in vain. Forty of her bravest had risked themselves, almost all of them suffer burns, and four of them have died. On the night of the third attempt, Drogon flies north across the Skahazadhan toward the tall grasses of the Dothraki sea, and does not return. His whereabouts are unknown for a long while. There are reports that he has been seen north of the river, above the grass of the Dothraki sea.

Drogon never returns to Dany at the Great Pyramid, and Tyrion doesn't definitely see him on the way to Meereen—however, he does glimpse a flying creature with leathery wings, who may well be Drogon, in the same chapter that is being adapted in the scene which unambiguously includes him in the TV series.

Drogon does not come to Daznak's Pit in the books to save Daenerys; he is drawn to the Pit by the smell of blood and fresh meat from the recent of the gladiatorial battles (some involving animals), that results in the death of a pit fighter named Barsena Blackhair. Daenerys is amazed to see how much he has grown while being away: his wings stretch twenty feet from tip to tip and make sounds like a clap of thunder.

Many of the spectators flee, but an animal handler named Harghaz takes it on himself to be a hero. Daenerys thinks that perhaps he is drunk, or mad; perhaps he has loved Barsena Blackhair from afar, or has heard some whisper of the girl that Drogon killed; perhaps he is just some common man who wants bards to sing of him. Whatever his motive is, he leaps onto Drogon's back and drives his iron spearpoint down at the base of the dragon's long scaled neck. Daenerys and Drogon scream as one. As Harghaz tries to drive the spear deeper, Drogon throws him off his back, then wrenches his forearm.

Hizdahr yells to the other spearmen "Kill the beast!" Daenerys cannot restrain herself, rushing to help Drogon. The spearmen run too, the brave ones in Drogon's direction and the wise ones away from him. Drogon spits fire at the spearmen, burning two of them to death; his tail breaks the pitmaster (who snuck up behind him) into two pieces; another attacker stabs at his eyes, until the dragon catch him in his jaws and tears his belly out. Daenerys approaches Drogon; he roars full in her face, his breath hot enough to blister skin. He bathes her in dragonfire, causing her to lose her hair and clothing. On Daenerys's right, Ser Barristan Selmy tries to draw Drogon's attention to him. Daenerys grabs the dead pitmaster's whip and hits Drogon repeatedly, till he obeys her. She jumps on his back, pulls the spear from his neck, and they fly away.

Two hundred and fourteen people are slain in the arena, either killed by Drogon or trampled to death in the commotion, and three times as many are burned or wounded. Drogon has gone from the city by then, last seen high over the Skahazadhan, flying north.

Drogon takes Daenerys to his lair in the Dothraki sea. He allows Daenerys to ride on his back, but not to turn him to the direction she wants. Daenerys knows that the dragonlords of old Valyria had controlled their mounts with binding spells and sorcerous horns, but she has none; her whip only annoys him rather than hurt him. Wandering about, they spot a herd of horses. The riders flee, and Drogon catches one horse. He and Daenerys share it, when she suddenly hears approaching horses. She stands beside her dragon, as Khal Jhaqo and fifty warriors encounter her.

Daenerys refers to her three dragons as "brothers", but there is actually no specific reason to think that their eggs were all laid by the same dragon, or if the three eggs were even found in the same place or gathered individually. She may call them "brothers" more in the figurative sense that they were raised together.