•Apocalyptic and post-apocalyptic fiction: concerned with the end of civilization either through nuclear war, plague, or some other general disaster. Post-apocalyptic fiction is set in a world or civilization after such a disaster. The time frame may be immediately after the catastrophe, focusing on the travails or psychology of survivors, or considerably later, often including the theme that the existence of pre-catastrophe civilization has been forgotten (or mythologized). Post-apocalyptic stories often take place in an agrarian, non-technological future world, or a world where only scattered elements of technology remain.
There is a considerable degree of blurring between this form of science fiction and that which deals with false utopias or dystopic societies. • •Dark fantasy: a subgenre of fantasy which can refer to literary, artistic, and filmic works that combine fantasy with elements of horror. The term can be used broadly to refer to fantastical works that have a dark, gloomy atmosphere or a sense of horror and dread and a dark, often brooding, tone. •Gnome, being of earth (gnomus).
He describes them as two spans high, very reluctant to interact with humans, and able to move through solid earth as easily as humans move through air.   •Undine or nymph being of water Undines are almost invariably depicted as being female, which is consistent with the ancient idea that water is a female element.  They are usually found in forest pools and waterfalls, and their beautiful singing voices are sometimes heard over the sound of water. •Sylph, being of air (sylevestris) is a mythological spirit of the air •Salamander, being of fire (Vulcanus).