<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>