Demon Dragon

	My body... My mind... Everything! I'll sacrifice it all to destroy you... and cast this world into eternal night!
— Ganondorf before becoming the Demon Dragon

The Demon Dragon ^(TotK) is introduced in Tears of the Kingdom as the third and final phase of the Final Boss battle. This dark creature is the embodiment of Ganondorf's power, but holds none of his original personality except a desire for pure destruction.

Overview

Upon realizing Link's strength is too much for him to handle, despite his formidable power as the Demon King, Ganondorf desperately undergoes draconification, by swallowing his Secret Stone of Darkness, with the destruction of everyone now his only desire. After becoming the Demon Dragon, he seizes Link in his jaws and flies upward through the Hyrule Castle Chasm, breaking through to the surface. However, he is confronted by the Light Dragon, the draconified form of Princess Zelda, who saves the hero from the Demon Dragon's clutches. With the fated trio reunited once more, Link and Zelda prepared to finish off Ganon for good.

Characteristics

	The form that Ganondorf, the Demon King, attained after swallowing a secret stone and attaining his true power. No trace of his original form remains. Its overwhelming magical strength would shake the skies. The jet-black scales covering it repel any and all attacks, save for those of the one and only Master Sword.
— Hyrule Compendium

As the Demon Dragon, Ganondorf is given the title of Draconified Demon King, and takes the form of an Immortal Dragon with jet black scales and red spikes adorning its back, along with a fiery red mane and dozens of sharp horns on its head. Curiously and perhaps oddly, both it and the Light Dragon have monocular vision (their eyes are located on the side of their heads rather than at the front), a feature usually reserved for prey animals, while predators tend to have binocular vision.

Tears of the Kingdom

Hyrule Compendium Entry

XXX (XXX) Demon Dragon File:BotW Hyrule Compendium Demon Dragon.png	Description The form that Ganondorf, the Demon King, attained after swallowing a secret stone and attaining his true power. No trace of his original form remains. Its overwhelming magical strength would shake the skies. The jet-black scales covering it repel any and all attacks, save for those of the one and only Master Sword.
	Common Locations Unknown
Recoverable Materials None

Similar to Dark Beast Ganon in Breath of the Wild, the battle is relatively simple in execution. In order for Link to deal damage, he must direct the Light Dragon above the Demon Dragon so he can jump off, landing on the Demon Dragon while avoiding the Gloom blasts fired from its mouth. Upon landing, the Hero of the Wild must attack four weak points - all bubbling pustules of eyes concentrated in pits of gloom on the Demon Dragon's back. After destroying a weak point, the Demon Dragon will attempt to throw Link off, but the Light Dragon will retrieve the hero again to continue fighting. Outside of the four pits where the villain's weak points exists, the entire dragon's body is coated in Gloom, which will cause Link to suffer damage so long as he walks on those scales. Being hit by a Gloom blast will permanently remove one full Heart Container from Link.

The final weak point is the Secret Stone on the Demon Dragon's forehead, which is moderately more difficult to target due to his Gloom blasts being much closer. Upon reaching the weak point, two swings of the Master Sword will cut through the rest of the Demon Dragon's health bar. After a short scene of the Demon Dragon writhing in agony, Link is prompted to deliver the final blow by thrusting the sacred blade onto the monster's forehead, which results in a large vertical explosion of Malice and Light, finally vanquishing the Calamity that has plagued the land of Hyrule for so long and Ganondorf himself being ultimately slain.

Trivia

Upon his initial transformation in the Depths, the Demon Dragon bears a striking resemblance to the incorporeal form of Calamity Ganon from Breath of the Wild.
The appearance of the Demon Dragon is similar to Volvagia, the boss of the Fire Temple from Ocarina of Time, as well as the dragons seen in the game's prequel.
The Demon Dragon's snout bears a heavy resemblance to that of a boar's, a likely reference to the standard form of Ganon seen in most previous entries of the series.
Considering Ganondorf's large size compared to other characters, the Demon Dragon is significantly larger than the Light Dragon.
Ganondorf's loss of personality upon a transformation is reused from himself turning into his beast form in Twilight Princess. Unlike the Demon Dragon, however, the Dark Beast from Twilight Princess reverted to Ganondorf to his Gerudo form upon clashing with Midna.

Gallery

Demon Dragon introduction
Link preparing to fight the Demon Dragon with the help of the Light Dragon (Princess Zelda)
Ganondorf upon turning into his dragon form