Here are some DIYs and inspirations to turn old dolls or doll parts into a dreadful decoration for Halloween.
Savers has instructions on DIYing your old old 11 inch "Fashion Dolls" into creepy decorations with some white and black paint. The site that I read about this tutorial, "This Mama Makes Stuff" has transformed a whole bunch of old dolls into a "Barbie Zombie Garden".
If you want to make a more gholish looking doll EBSQ Self Representing Artists has instructions to make this devilish looking doll.
Photos by EBSQ Art
Photo from Interbent
See Barbie Of The Undead and 1000's of others - or share your own on Cut Out + Keep
See Zombie Barbie Trophy and 1000's of others - or share your own on Cut Out + Keep
See Kasey Kasket and 1000's of others - or share your own on Cut Out + Keep
See Baby Head Paper Weight and 1000's of others - or share your own on Cut Out + Keep
See Siren Barbies and 1000's of others - or share your own on Cut Out + Keep
You could also put in jar with colored water as a "specimin" like this picture by amucci on Flickr (although I have no idea how she got the doll in a clear dish soap bottle!
Here are some links to more extreme alterations - some have inspirations that you might be interested in, but a few are just too over the top for me.
Vintage Antique Collectibles
Little Dead Girl Creepy Dolls
New Age Dolls
If you have your own creepy altered doll links, feel free to post in the comments section below.
Happy Haunted Crafting!