Chthonic
( /ˈkθɒnɪk/, from Greek χθόνιος – chthonios, "in, under, or beneath the earth", from χθών – chthōn "earth"; [1] pertaining to the Earth; earthy; subterranean) designates, or pertains to, deities or spirits of the underworld, especially in relation to Greek religion. The Greek word khthon is one of several for "earth"; it typically refers to the interior of the soil, rather than the living surface of the land (as Gaia or Ge does) or the land as territory (as khora (χώρα) does). It evokes at once abundance and the grave.
one of the chthonic dieties is gaia.
there is also a band from taiwan.