Sternfathom's Pet Journal

Sternfathom's Pet Journal summons a ghostly Shipwrecked Captive who offers the weekly quest Shipwrecked Captive (quest).

Source
This item is looted from a Treasure Chest in Azsuna. Slavehunter Zsanesh, guards the chest and will need to be killed before the player can open it safely.

The chest was dropped by an escaping gnoll slave that had stolen it, and Zsanesh had just dispatched it.