- "The source of the darkness that has appeared time and again throughout Hyrule's history. It's been called many names, from "Great King of Evil" to "Calamity." Hibernating within a cocoon, it attempted to regenerate a physical form after Link awoke but was forced to confront him in an incomplete state."
- — In-game description
Calamity Ganon is the main antagonist and penultimate boss in The Legend of Zelda: Breath of the Wild. He is the last Scourge, found at Hyrule Castle. He is an incomplete form that Ganon assumed when he was interrupted while trying to reincarnate himself.
Calamity Ganon first emerged in the distant past, but was defeated by an army of mechanical Guardians and four massive mechanical constructs called the Divine Beasts, that the Ancient Sheikah tribe developed with their unique technology.
Ten thousand years later, a prophecy of Calamity Ganon's return drove King Rhoam of Hyrule to create an archaeology team to recover the Divine Beasts and Guardian army in preparation. They were successful in not only recovering these relics of the Sheikah's Ancient technology, but were also able to reactivate and use them.
The King selected the hero chosen by the Master Sword, a young recruit of the royal army named Link. Link was appointed as the personal knight of his daughter, Princess Zelda. King Rhoam decided to create a group of warriors and protectors, the Champions among whom Zelda would be the Commander assisted by her knight, the Hylian Champion. King Rhoam additionally requested each race of Hyrule choose a Champion who would individually pilot one of the Divine Beasts. The final key to defeating Calamity Ganon was the Divine Power of the royal family's bloodline, and the recent death of Hyrule's Queen saw this immense duty fall to her only surviving daughter, Princess Zelda. As she was now sole bearer of their birthright, the King charged Zelda to focus on mastering her control over the Divine Power to the exclusion of all else, and duly appointed Link as her personal knight and bodyguard to ensure she stayed safe.
However, all of this preparation proved to be in vain, as Calamity Ganon was prepared for Hyrule's attempt to repeat history; he sent four wraith-like incarnations of himself to corrupt the Divine Beasts and slay their Champions, while using his own dark power to take control of the Guardians and use them against the people of Hyrule. With the heroes' defenses crumbling, and even Link overwhelmed by the renewed assault, Zelda was able to use her Divine Power to seal Calamity Ganon within Hyrule Castle.
Over the next century, Ganon bode his time within his prison, draining Zelda's divine power in an attempt to gain the strength to break free from the waning seal. His growing power allowed his Malice to spread throughout Hyrule, and following Link's resuscitation he entered a cocoon of Malice to regain physical form. Ganon's reincarnation was still incomplete by the time Link confronted him in the depths of the corrupted castle. After a fierce battle, Calamity Ganon was struck down, disintegrating into eerie smoke; however, he soon reformed as the even more monstrous Dark Beast Ganon. Following his defeat as Dark Beast Ganon, he returns to his spectral Calamity form before being sealed away by Zelda.
Calamity Ganon first appears as a boar-shaped spectre made of Malice, possessing an enormous mouth, tusks, and glowing yellow eyes. In his partially-regenerated form, he is a spider-like abomination resembling the Blights he sent to corrupt the Divine Beasts, being composed primarily of solidified Malice augmented with the Ancient Sheikah technology. His upper body is roughly humanoid, with wild red hair and a skull-like head vaguely reminiscent of Ganondorf's visage. His lower body is a bloated mass of Malice half-plated in armor resembling the body of a Guardian Stalker, complete with two of its four-clawed limbs protruding from the back.
Calamity Ganon has several arms all over his body; most are almost emaciated looking, save for a massive right arm that ends in a glowing orange blade similar to Fireblight Ganon's weapon. One of his left arms carries a blue spear similar to Waterblight Ganon, while another ends in a slightly smaller version of Windblight Ganon's beam cannon. He also has three mechanical limbs on his back, each with different energy blades; the left has a shear-like pincer, the middle has a hand with energy claws for digits, and the right has a small sword resembling the one used by Thunderblight Ganon.
If any of the Divine Beasts were liberated before Link confronted Calamity Ganon, the fight will start with a cutscene where the spirits of the Champions that Link freed command their Divine Beasts to attack, blasting Ganon with a rain of energy beams. Each Champion's attack depletes one-eighth of Calamity Ganon's health; if all four were freed prior to the battle, he loses half of his health before the fight even begins.
In addition to the above, if Link found the Master Sword prior to going to Hyrule Castle, a short cutscene shows him drawing it and igniting the blade with divine power before the battle with Calamity Ganon begins.
Most of Calamity Ganon's attacks are more elaborate versions of the moves used by his Blights. He can use the Waterblight's energy shockwave and spear throw, the Fireblight's burning blade swipes (horizontal or vertical) and charged fireball, the Thunderblight's lightning spikes, and the Windblight's tornado and laser blasts. He can also fire powerful laser beams,similar to Guardian Stalker's one, slash and stab at Link with his back appendages, and crawl on the wall to keep himself out of reach.
After being reduced to half of his starting health (i.e. the health he had after the Divine Beasts' attack), Calamity Ganon will glow orange, rendering him immune to damage. The only way to hurt him at this point is to make the aura disappear, either by performing a Perfect Dodge, knocking Ganon down by reflecting his projectiles (spear, laser beam, fireball, and bullets) back at him, or using Urbosa's Fury. His aura also disappears for a brief moment after he attacks, so well-timed arrows or other attacks can hit him even without a Perfect Dodge.
As with all of the Scourges, Calamity Ganon takes extra damage from Guardian-based weapons and the Master Sword.