Netsuke: Elaborate miniature carvings made (usually in Japan) to secure purses to Kimonos or Kosodes. Materials vary, Ivory and boxwood were once common, now it's mammoth ivory if you're lucky, otherwise cheap resin or plastic. There are an almost limitless variety of them (the handmade ones at least), here are a few searches to get you started:
On Flickr, and again here. On google images here: skull netsuke, or for the more adventurous try erotic netsuke.