ACROSS

 2  He brings death
 4  Scary holiday
 7  A graveyard
 8  An unlucky symbol
11  Jack-o'-lanterns
13  It spins a web
15  Hide behind it
16  Mummies and vampires use these
17  Vampire's favorite drink

DOWN

 1  Mary Shelley wrote a story about him
 2  Comes back to haunt you
 3  Scary flying mammal
 5  Dug for the dead
 6  Witches stir it
 8  Witch may ride one
 9  Bob for them
10  Bones
12  Wolves howl at it
13  Witches cast these
14  Famous vampire