Magical cloak that acts as armor. Protection against normal and magical attacks as well as holy spells. Gives creatures who are harmed by light and sunlight immunity. Give wearer the ability to become invisible at night. Sentient and cursed. See full description for details.
Consider the idea of spontaneous genesis of life, as used to be belived. What strange kinds of life might arise from modern substances? What kind of vermin would a landfill produce, or an oil spill on the ocean?