Print tooth template on card stock and cut out shape.
Trace shape onto white felt with a water-soluble marking pen, and cut shape from felt.
Embroider face onto tooth with black embroidery floss. The eyes are French knots (get the French knot how-to); the mouth is created with a backstitch (get the backstitch how-to).
Cut two pieces of 9-by-9-inch fabric. Hoop one piece of fabric in an embroidery hoop, and pin tooth in center.
Hand-stitch around the edge of the tooth with white thread, leaving the top open so the tooth becomes a pocket.
Remove fabric from hoop and place appliqued side down on other square of fabric. Pin in place. Sew pieces together around edges with a 1/4-inch seam allowance, leaving a 4-inch opening for turning right side out.
Trim corners of seam allowance and turn right side out. Stuff with batting and hand-stitch opening closed.