<canvas width="600" height="400"></canvas>
<script>
    var pantalla = document.querySelector("canvas");
    var pincel = pantalla.getContext("2d");
    //cabeza
    pincel.fillStyle = 'darkgreen';
    pincel.fillRect(0, 0, 350 ,300);
    //ojos
    pincel.fillStyle = "black";
    pincel.fillRect(50,50, 90,90);
    pincel.fillRect(210,50, 90,90);
    //nariz
    pincel.fillRect(140,140, 70,100);
    //bocas
    pincel.fillRect(100,190, 40,110);
    pincel.fillRect(210,190, 40,110);
</script>