Special Exposure Wednesday

This strange flower (?) popped up in my side garden. It grew about 3 feet tall right in the middle of my iris bed. At first, it just looked like a ball (about the size of a gumball) sitting on top of a long skinny stem. Then it started to open up and look like this. We're calling it the alien flower, but if anyone has a clue as to what it really is, please tell me!