Update: More information on this object clearly explained here!
This interestingly shaped thing is a kind of planetary nebula. From my understanding (note: I am not an astronomer!) its appearance is quite green because it is poor in hydrogen. If you want to know more, some papers about it are here.
Object name: PK208+33D1
Coordinates: 08:46:53.370 +17:52:44.40
Hubble data is public domain, but I put a lot of work into combining it into beautiful color images. The minimal credit line should read: NASA / ESA / J. Schmidt
This work is licensed under a Creative Commons Attribution 3.0 Unported License.