This example shows a simple cartoon face built from SVG shapes, including a yellow circle, eyes, animated eyebrows, and a mouth drawn with an arc path. The eyebrows move up and down repeatedly using D3 v4 transitions that alter their transform attribute. The code uses D3 selections, the `arc` function for the mouth, and SVG elements such as `circle`, `rect`, and `path`, with styling applied via a linked CSS file. Rendering is done entirely in SVG with no external data source.