The grave digger is an archetype that shows up in many pieces of art. Whether in medieval fantasy, Victorian surroundings or even modern day, the image of a grave digger is often ghoulish, giving an impression of a comfort with the dead and the dreary surroundings of the graveyard that normal people just don't have. If you want to draw a grave digger, it's a project with a lot of creative license, and where the scene makes the character.
Draw a skeletal outline of the grave digger. Draw a circle for the head, and single lines for the bones of the arms and legs connected by circles for the joints. Draw circles for the hands, and rough triangles for the feet. Fill in the rib cage. You're trying to get a general feeling for the pose that the grave digger is going to have. Standing up straight, crouched over or leaning on a shovel planted into the ground, you need to figure out the general pose before you can do anything with detail.
Firm up the general outline of your gravedigger. Add a jaw to the head, and mark with a horizontal line where the eyes will be. Add a vertical line to show where the centre of the head will be and to give yourself an idea of where the grave digger will be facing. Turn the single wires of the arms and legs into rounded pipes more like actual limbs. Fill in the hands with knuckles, and thinner pipes for the fingers, showing how the grave digger is holding himself. Add in details like eyes, nose, mouth and hair to the grave digger to begin filling him out.
Draw in the outline of the grave digger's clothes and the background. These elements will hint at what the grave digger is and what he does. Heavy work boots are a start, along with rough trousers that have patches or holes in the knees. Add a workman's shirt, rolled up at the sleeves and maybe a pair of work gloves to show he works hard. A field of gravestones, or a hand truck with a covered corpse on it is a good start. An open hole, or a nearby coffin, are also good props, as is a tree curling up in the moonlight behind to lend atmosphere.
Add details to the grave digger's form: mud spatters on his boots and gloves, and outlines of the muscles in the chest and arms. Digging graves is hard work. Make the face lined and a little haggard, possibly with some stubble. He keeps the company of the dead, and the dead don't care if he cleans up before coming to work.
Add details to the background. Drawing in the form of the corpse beneath the shroud, adding inscriptions to the gravestones, and heavy shadows from the moonlight or along the ground all add to the eerie scene. Of course, the grave digger should look at ease and unaffected by the creepy scenario, because for him this is his regular job.
Always erase old lines that you don't need anymore. Use references from the time period you're trying to portray. A workman from the feudal era will dress differently than one from Victorian London, but the same dirty job is being done, and it builds the same muscle tone and leaves the same smears on the grave digger's clothes. References to muscle build, pose and shadowing are also good to help achieve the proper detail.