Board Thread:Dark Souls/@comment-124.149.114.115-20130127065257/@comment-1687225-20130127065440

You can complete Siegmeyer's story (see his page for more details). If you have the DLC, there is one in a chest behind the waterfall where you fight Kalameet. Both take quite some time to fully accomplish...

Dark wraiths drop them, but only extremely rarely. Crystal lizards in the great hollow drop them uncommonly.