Whimsical Koala Guard at the Fortress

A charming cartoon-style koala wearing a tiny knight's helmet, standing on the crenellated battlements of a grand stone fortress. The fortress features tall towers, a drawbridge over a moat, fluttering banners, and warm torchlight illuminating the scene. The koala holds a rolled parchment or a toy sword, striking a heroic pose with a big friendly grin, big round eyes, and fluffy cheeks. Art style is bright, bold outlines, simple shapes, soft shading, and pastel yet saturated colors in a classic 2D cartoon/vector look. Composition is a mid-shot, 3/4 view, center-focused with the fortress stretching into the background for depth; mood is playful, adventurous, and whimsical.