The derelict ship is a creature bank in Heroes of Might and Magic II, Heroes III, and Heroes IV.
Heroes II derelict ship
In Heroes II, the hero fights skeletons and is rewarded with gold.
Heroes III derelict ship
In Heroes III, the hero fights water elementals and is rewarded with gold and artifacts.
Heroes IV derelict ship
In Heroes IV, the hero fights water elementals and is rewarded with gold.