Dust Devils

Dust devils are a monsters that lurk deep underground. Monsters made of magic their "bodies' are made complexly from sand. Their torsos are spinning twisters of sand. Their heads are balls of spinning sand with green glowing eyes. The can form hand and arms to attack from the sand from their bodies. Normal attacks won't phase a Dust Devil, you must use magical attacks against them. Magic won't completely kill them though, only stun them. A Dust Devil's weakness is in their torso. In their tornados of sand hides a gem. If this gem is removed the Dust Devil falls apart.
They attack with their sand, blinding foes and ripping them apart with high pressure sand streams. Their sand can latch onto their enemys and crush bones. So if your exploring underground make sure you have a mage with you.