First of all create a new Photoshop document with dimensions of about 140 width by 140 height. We're going to start off by creating his head, so create an oval shape on a new layer, like in image a). Zoom in to 200% and then contract (select > modify > contract) the selection by 1 pixel, deleting the centents of it. Make another new layer and then create a second oval, also deleteing the contents of the selection. We don't need the whole of the second shape, so use the eraser tool to delete some of it, like in image d).

You should be left with a curved line which will be the side of his face. Duplicate the layer and then move it over to the left, for the other side of his face. Flip the curved line horizontally (edit > transform > flip horizontal). Next, erase part of the 1st shape, as shown in image b). Make a new layer, create a circle, and delete the center, as we did with the previous 2 shapes. We only need the part of this top part of circle that's inbetween the sides of the face, so delete the rest.