King Gan, also known as the White Lightning by the bats and "Old Gan" by the dwarves, was a large white cave snake living shortly before the Age of Fire in the Lower World.
He was known to be double the size of a dragon hatchling. The snake claimed for himself the title of "King" being a fearsome creature and having power over the other snakes (power triggered by fear because King Gan was known to eat also other snakes). He was feared by many other animals including bats: he's known to have eaten both the father and one uncle of Thernadad.
The Copper faced King Gan and defeated him, thanks also the help of Thernadad, because the large snake was able to block the enemy with his powerful glance before biting him.
Later the snake returned after having gathered other snakes to kill the Copper and the bats: many bats were eaten, but the Copper managed to escape with few of them.