mi solución
<canvas width="600" height="400"></canvas>
<script>
let pantalla = document.querySelector("canvas");
let pincel = pantalla.getContext("2d");
//cabeza
pincel.fillStyle = "darkgreen";
pincel.fillRect(0,0,350,300);
//ojo izq.
pincel.fillStyle = "black";
pincel.fillRect(50,50,90,90);
//ojo dere
pincel.fillStyle = "black";
pincel.fillRect(210,50,90,90);
//nariz
pincel.fillStyle = "black";
pincel.fillRect(140,140,70,100);
//boca lado izq
pincel.fillStyle = "black";
pincel.fillRect(100,190,40,110);
//boca lado dere
pincel.fillStyle = "black";
pincel.fillRect(210,190,40,110);
</script>
