Gnomes are an offshoot of dwarves originally featured in Renaissance mythology. They are humanoid fairies of minuscule size. They live underground where they mine for treasure. They also experiment in Alchemy (a combination of Magic and Science originally developed in the hopes of turning base metals into gold).
Gnomekind's obsession with acquiring wealth has brought them to the very bowels of the Earth, from which they exercise virtually no interaction humankind, and when they do it is often unpleasant. This is mostly due to the fact that gnomes (like their dwarvish kin) are slaves to their greed, and are often evil as a result.
The only gnomes that interact with humans regularly are a troublesome subspecies known as garden gnomes. They burrow in soft soil, feed mainly on roots, and are kleptomaniac. Due to this; they infest gardens and are little if not nothing more than pests.