This category is for life made out of unordinary matter, which differ in some properties from that which is based on the ordinary molecular matter that forms planets, main sequence stars and nebulae of our familiar surroundings.
These exotic life forms may be based on atoms, but arranged in forms other than the regular states of matter (solid, liquid, gas and plasma) such as neutron-rich fluids of pulsars, or the immaterial singularity of a black hole. They may be made of particles other than electrons and triple-quark composts (protons and neutrons), including substances that may account for what is known as dark matter. They might exist entirely or partially outside our tridimensional space, or belong to alternate universes and realms where the laws of physics differ. They might be made of antimatter, or some yet-undiscovered essence; or they might be combinations of any of the above. One step further and you have energy life.
NOTE – Species made out of ordinary matter, but possessing different biochemistries than ours should be directed to their specific categories (e.g. Category:Silicon-based Species). This one should be reserved for truly exotic, hard-to-describe life.