The Silence is a creature whose origin is unknown. Long ago, it fought the sorcerer Raama. Raama won and sealed the Silence away in a crypt called the Skull of Silence. Because the sea was the Silence's weakness, Raama imbued a gong that when struck gave off the sound of the sea that was to be used to keep the creature at bay.
Long after Raama's passing, King Kull foolishly released the Silence from its prison despite warnings not to do so. The Silence nearly killed Kull, but Kull was able to subdue it by striking the gong, though he hit it with too much force and destroyed it. Kull quickly sealed the Silence away and declared that no one should ever open the doors again.
Powers and Abilities
The Silence has the power to rob an area entirely of its sound, driving living things in the area mad.
The Silence apparently is vulnerable to the sea or doesn't not like it immensely. Even the sound of the sea is enough to weaken it. It was vulnerable to a gong imbued with the sound of the sea, but it was destroyed when Kull hit it too hard.