Menhir

From Glen Cook Wiki

Menhirs are moving, living creatures native to the Plain of Fear and the main spokespeople for Old Father Tree. They look like standing stones, gray brown, mostly, without visible orifices or organs. Most are as shaggy with mosses and lichens and bugs as any normal boulder. They range from ten to eighteen feet tall and speak in deep, cruel voices. They have wicked senses of humor. Their movements are sudden and jerky, and they appear in new locations accompanied by the sound of clapping thunder, but only do so when they are not being watched. Mehnirs tend to be cryptic when they speak. If slain, their remains are taken (presumably by menhirs, or perhaps other Plain creatures) and righted near a creek ford on the Plain, the menhirs' equivalent of a cemetery.