Stone Giants are one of the six "major breeds" of Giant in Dungeons & Dragons. Characterized as generally Neutral in attitude, Stone Giants are most famous for their obsession with artistry, spending most of their existence honing their skills in the art of stone carving and rock throwing. Despite being one of the bigger giant breeds, they prefer to live underground, even delving deep into the Underdark. They are quite isolationist, though this isn't uncommon amongst the few non-evil Underdark societies, and they rarely leave their territory.
In fact, stone giants are so used to their quiet underground homes that they regard the surface world as nothing but a dream; changeable, ephemeral, and thus less real than the Underdark. Stone giants on the surface thus behave in a very Chaotic Stupid manner- after all, there are no consequences to what one does in a dream. Stone giants who lose themselves to the dream and choose to live on the surface are called Dreamwalkers, and they're so divorced from reality they can actually petrify people around them.