The Underdark is a vast subterranean realm inhabited by drow, mindflayers, aboleth, and other strange, sinister creatures. It is a place where few humans go and from where even fewer return".
The Underdark is described as a strange, alien setting, entirely underground. Bizarre creatures and ancient races populate it, nearly all of whom are of hostile nature.
The Underdark is extremely dangerous, especially to creatures that are not native to it. There are the usual dangers associated with caverns: claustrophobia, occasional poor air circulation, and getting lost. Cave floor and ceiling collapses are also a hazard.
There is no light except for occasional patches of phosphorescent fungus; most Underdark inhabitants either have highly developed senses other than sight or have developed Darkvision. Food can be extremely difficult to find, and much of the natural vegetation is poisonous. In addition, potable water is seldom easy to locate.
Drow pets and Monsters are available in my catalog.