A caterpillar built from stacked SVG ellipses and rectangles demonstrates primitive shape composition. The code renders a segmented body with varying radii and fill colors, plus legs, eyes, and antennae using `<ellipse>`, `<rect>`, `<circle>`, and `<path>` elements. Each shape is positioned manually via `cx`, `cy`, `x`, and `y` attributes within a fixed 960×500 viewport. The example uses raw SVG markup without any JavaScript libraries, showcasing static vector graphics in a plain HTML document.