The Leather Slingshot is an item found in both versions of KQ1. 
While in the Land of the Clouds, Graham discovered a leather sling (or toy slingshot) hidden inside a tree. He has the option to use it-along with the pebbles that can be collected on the bank of the River Fools (or on the beach by a lake)-to kill the giant that was protecting the Chest of Gold. He didn't, but he could have.
It is a toy slingshot. It is a small but sturdy slingshot. A leather pocket between two pieces of elastic material and tied to a y-shaped frame.
Behind the scenesEdit
This item is called the "leather slingshot" in KQ1AGI, and "Leather Slingshot" in KQ1SCI.
The item as it appears in KQ1AGI is usually described as the 'sling' or 'leather sling' it is only described as a 'slingshot' twice in the game (under the inventory title 'leather slingshot' and when the game points out that the 'slingshot' is being used too close to the giant for it to be effective, and suggest that the player runs). Beyond that the game understands 'slingshot' and 'sling' in the parser.
Due to this the item is called the "Sling" in KQ1 hintbook. The sling is also the name of the item as it appears in the inventory in King's Quest 1 for the Sega Master System.
In KQ1SCi it is generally described as a 'slingshot' but also by 'sling'. There are more references to its use against various characters in the game.
In the original KQ1 the slingshot was a traditional sling (like the one in the bible story). A single strip of leather with a pocket for pebbles that could be swung at a target. The game describes the weapon as a 'sling' when looking at it.