Summarize:

Tease some clay from your central ball to the back to create a tail. A thick base connecting your tail to its body will create sturdiness in the finished product. Avoid making your tail too long, as this can crack during backing or harden in a way that is brittle and delicate. Push down slightly on the base of your tail to give the effect that the tail is coming out from between the dragon's legs, and not from the top of your clay ball, which will eventually turn into the back of your dragon. Wings can be tricky, and while learning the basics of sculpting you may want to keep your wings thick and small. Create your wings by pulling some clay from either side of the top of your clay ball. If you find that you need more clay, knead a small piece and use your thumb to blend the new clay with that of your clay ball, and then work this clay into the simple shape of a wing on both sides.  Thick wings will keep the clay from cracking there when you bake it and will result in a sturdier sculpture. The wings, being such a delicate part of the sculpture, are the most fragile and breakable part of the dragon. Exercise care while forming these. Your dragon may be a hornless variety, but if you had planned on making a horned dragon, take a small amount of surplus clay and knead it in your hands. Then, shape two cones for your horns and lightly press each into the head of your dragon. Use a little water to dampen the base of your cones. This can help keep your horns in place. It's likely that your clay ball is still mostly round at this point, with limbs, head, tail, wings, and horns attached. However, the bodies of dragons are usually more elongated and oval in shape. Press gently on the rounded sides of your clay ball to squish the circular shape into a longer oval one. At this stage, your dragon should be mostly formed, but you should consider using a little extra clay and your knitting needles to add a ridge along the back of your dragon. This can be done by:  Kneading some extra clay. Pulling off little pieces. Rolling tiny cones, damping the base of the cones, and pressing the cones along the spine of the dragon. Adding a contour line with your knitting needles to either side of the spine. Dragons, in most mythologies, have bat-like wings. These often come to a point at the highest point and have some bones dividing the wings into parts or sections. Using your finest knitting needle, you should carefully:  Trace a line along the inside of the outer boundary of your wing. Add lines from the top of the wing to the bottom of the wing, splitting each into regular sections. Avoid thinning your wings too much or applying too much pressure. Thin clay cracks easily when baked or after being baked, and even well formed wings will be delicate. The small size of this amateur model will limit the amount of detail you are adding unless you have a very steady hand and very precise needles. However, you should be able to use your knitting needles to gently carve out the shape of two eyes and a mouth line around the outer rim of your triangular head.
Add a tail. Create wings for your dragon. Shape and affix your horns, if desired. Elongate the body of the dragon, if necessary. Detail the body. Give features to your wings. Give your dragon a face.