The aranasi are a race of spider-like demons. Their origins are not fully understood - scholars who have studied the Burning Legion speculate that they are the remnants of a forgotten race on a world long ago conquered by the armies of Sargeras.
Brood Queen Tyranna is an aranasi who rules Mardum and protects the [Sargerite Keystone].
Some of them appear to look like typical spiders. Pools of an orange fel-like substance can be found in their lairs, though what this is is unknown.