The term stone giant refers to two or more different, yet possibly interconnected, titan creations. All are, of course, giants made of stone.
Stone giants (also called wood giants) are found primarily in Northrend. They look like mountain giants with trees sticking out of their backs, and roots wrapped around their heads. These stone giants look more like a type of colossus. Some of the stone giants are rune-inscribed, the runes control the giants.
Stone giant (model)
Some of Northrend's stone giants (possibly called rock-giants) are more detailed appearing more human-like with carved beards, and armor. One of their hands seems to have been replaced with a spiked boulder. These seem the most similar to the other four types of titan-made giant, but rather dissimilar to other "stone giants."
Known stone giants
Named stone giants
Other stone giants