Cute Crayon Koala Character

Create a simple centered children's-book illustration of a cute full-body {argument name="animal" default="koala"} character on a plain white background. Use a hand-drawn crayon or thick marker style with rough, slightly wobbly black outlines and soft textured gray fill. The character faces forward, standing upright with a large rounded head, rounded body, short arms hanging at the sides, and short legs. Include exactly 2 large round ears, one on each side of the head, each with a black inner ear patch and no pink inner-ear color. The face has exactly 2 wide white circular eyes with tiny black pupils, 1 large vertical oval black nose centered between them, and 1 small curved smiling mouth below the nose. The body is {argument name="body color" default="warm medium gray"}, the outline is {argument name="outline color" default="black"}, and the overall mood is friendly, naive, and toddler-like. Keep the composition uncluttered, with no text, no shadows, no props, no scenery, and no extra characters.