The Stone Keys are objects that appear in Paper Mario: The Thousand-Year Door.
The Stone Keys consist of the Sun Stone and the Moon Stone. Both of these items are required to access Hooktail Castle so that Mario can get the first Crystal Star from Hooktail. However, Mario must venture into Shhwonk Fortress in order to get the Stone Keys. They are located opposite from each other and both are being guarded by Fuzzies. As Mario and Goombella try to leave, the Gold Fuzzy stops them not wanting them to escape with the Stone Keys. However, the Gold Fuzzy is soon defeated allowing Mario and Goombella to leave with the Stone Keys.