Aquí mi código
<!DOCTYPE html>
<html lang="es">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Poster de Creeper</title>
</head>
<body>
<canvas width="600" height="400"></canvas>
</body>
<script>
let pantalla = document.querySelector("canvas");
let pincel = pantalla.getContext("2d");
pincel.fillStyle = "white";
pincel.fillRect(0, 0, 600, 400);
// Cabeza
pincel.fillStyle = "darkgreen";
pincel.fillRect(125, 50, 350, 300);
// Ojos
pincel.fillStyle = "black";
pincel.fillRect(175, 105, 90, 90);
pincel.fillStyle = "black";
pincel.fillRect(335, 105, 90, 90);
// Nariz
pincel.fillStyle = "black";
pincel.fillRect(265, 195, 70, 100);
// Parte de la boca
pincel.fillStyle = "black";
pincel.fillRect(225, 240, 40, 110);
pincel.fillStyle = "black";
pincel.fillRect(335, 240, 40, 110);
</script>
</html>