Here is a pattern for a tiny witches hat. It is intended as a fascinator, jewelry to show your house colors from Hogwarts, but can just as easily be made in to a keychain object. The idea came from a fascinator along in the Hufflepuff house of the HPKCHC group here in ravelry.

It also fits a barbie or other dolls of that size.

You can find the pdf pattern here: https://drive.google.com/file/d/0B0fO__4oAKoXNWNiZGNkZDYt...