I have presented before the crocheted skull, but you can even crochet a whole shawl with crocheted skulls :)
Links:
Crochet Skull Shawl (Virkad döskallesjal. Med mönster // Crochet skull shawl. With pattern.) (Swedish and English)
via: Skull shawl/Döskallesjal
Here at unikatissima:
Crocheted Skull