Comparto mi código
<canvas width="600" height="400">
</canvas>
<script>
var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "darkgreen";//cabeza
pincel.fillRect(125,50,350,300);//1
pincel.fillStyle = "black" // ojos
pincel.fillRect(175,115,90,90)//2
pincel.fillRect(335,115,90,90)//3
pincel.fillStyle = "black"//boca central
pincel.fillRect(265,205,70,100)//4
pincel.fillStyle = "black"//boca lateral
pincel.fillRect(225,240,40,110)//5
pincel.fillRect(335,240,40,110)//6
</script> 
