The Spider Queen lurks in one of the darkest of Neopia's caves. She doesn't actively hunt other Neopets, but she has been known to attack if they venture into her web. She's also known to guard hidden treasures.
The Spider Queen was one of the first Gallery of Evil characters, and has since been completely removed from the site. Apparently she killed Rohnho the Nimmo and Tany the Lenny. However, it is unknown if they were Neopian characters, or actual user made Neopets that have since been deleted in a database purge.