Vah Rudania is a mechanical construct in The Legend of Zelda: Breath of the Wild. It is one of the four Divine Beasts. Vah Rudania is made from Ancient Sheikah technology; it takes the form of a giant salamander and is found on Death Mountain in the Eldin Mountains. Ganon sent Fireblight Ganon to corrupt it, transforming it into one of the main dungeons. Link must defeat this boss to free Vah Rudania.
One hundred years before the events of Breath of the Wild, Rhoam Bosphoramus Hyrule, his daughter, her Knight Link, along with four other Champions sought to seal Ganon through the use of the Divine Beasts and Guardians. Daruk, the Goron Champion, was in charge of controlling Vah Rudania.
Remembering his previous defeat at the hands of the Divine Beasts, Ganon sent out aspects of himself to subvert the Sheikah's technology with his evil power. Daruk met his demise by Fireblight Ganon, who then assumed control of Vah Rudania for the next one hundred years. Using the Divine Beast's power over fire and magma, Fireblight Ganon terrorized the Gorons with volcanic eruptions from Death Mountain.
Eventually, a reawakened Link sets out to free Vah Rudania from Fireblight Ganon's control. With the help of Yunobo, Daruk's grandson, the Hylian hero forces the Divine Beast into the crater of Death Mountain, allowing him to board it and slay Fireblight Ganon. This frees both Vah Rudania and the spirit of Daruk, with the latter taking control of the former once more. After giving Link his power and sending him on his way, Daruk guides Vah Rudania out of the crater, where it activates its main cannon and trains it on Hyrule Castle. When Link engages Calamity Ganon within the castle, Daruk has Vah Rudania fire a massive laser to weaken the monstrosity.
Like the other Divine Beasts, Vah Rudania's name is based on a Sage from a past installment in Legend of Zelda series. Rudania is a reference to and an anagram of the name of the Goron Sage of Fire, Darunia, from The Legend of Zelda: Ocarina of Time.