Create a graphic depicting a warrior in the style of World of Warcraft, but with a unique twist: the character is shaped like an onion. The onion warrior is clad in medieval armor and wears a helmet on its head. In its hands, it holds a shield and a spear, ready for battle. The whole image is designed to look like a sticker, with a clear and white background to enhance the sticker appearance. Emphasize the vibrant and cartoonish colors, and bold outlines typical of sticker art.