Askalaphos

Askalaphos was a demigod son of the river god Acheron and his Oceanid wife, Gorgyra.

Percy Jackson's Greek Gods
In Percy Jackson's greek gods, Askalaphos is described as looking like a zombie. He is the caretaker of Persephone's garden When she ate in the Underworld, Askalaphos ratted her out, and in revenge, Demeter transformed into a gecko.