Needle Felting

"Needle felting is a popular fibre arts craft created without the use of water. Special needles that are used in

industrial felting machines are used by the artist as a sculpting tool. While erroneously referred to as "barbed" 

needles, they in fact have notches along the shaft of the needle that grab the top layer of fibers and tangle them

with the inner layer of fibers as the needle enters the wool."

(Wikipedia - Felt - Needle Felting)