Source: Rise of the Runelords Anniversary Edition, pg(s). 121
The Scarecrow is a flesh golem that was created by Vorel Foxglove at the behest of the Brothers of the Seven over 100 years ago. At some point in the intervening decades, the golem's elemental spirit went crazy, which resulted in the Scarecrow gaining sentience. Parts of men, horses, and cows were used in building this golem. It is stitched very crudely and wears straw- and dung-covered rags.