Step 1: The rattlesnake's head looks like the outline of a large shoe, seen from the side. Start by drawing this without the far back end.
Step 2: About mid way up the top of the head, place the eyes and two folds on either side of them.
Step 3: Further up the head, place a dot to make the nostril.
Step 4: Draw lines to create the mouth that give just enough room for the eye and nostril, but very little room on the lower jaw.
Step 5: Put in two fangs like inverted coat hooks at the top of the mouth, below the eye.
Step 6: Draw the tongue on the lower jaw so it looks like a potato chip.
How to Draw a Rattlesnake Face – Step-by-Step Tutorial