B'gnu-Thun, also known as The Soul-Chilling Ice-God, is a Great Old One who features in H.P. Lovecraft's Cthulhu Mythos.
Almost nothing is known about B'gnu-Thun, although it has been reported to appear as a gigantic humanoid monstrosity with blue-tinged skin. Wherever it passes, a fierce, otherworldly blizzard follows in its wake, earning B'gnu-Thun it's epithet.
- The Call of Cthulhu (1928), by H.P. Lovecraft.
- The Seed of the Star-God (1984), by Richard L. Tierney.