An ancient Green dragon that resides within Cryptgarden Forest, Old Gnawbone is interested in the comings and goings of Waterdhavians. She is known to be a dragon that one can negotiate with for information, particularly about specific Waterdeep residents. To keep tabs on the folk she finds most interest in, Gnawbone has a collection of crystal balls she uses to constantly scry on the targets.
Laeral Silverhand has been able to procure such an item from the dragon - in exchange for what, the Trollmates don't know yet - in order to keep tabs on the group.