Bludgeon of the Grinning Dog

Bludgeon of the Grinning Dog is a rare two-hand staff.

This staff is a short stick that forms a Y-shape at its head. Between the points of the Y dangles a leather dog collar, to which a short leash is affixed. When the staff is wielded, the leash wraps itself about its owners wrist.

Source
This item drops from trash mobs in The Temple of Atal'Hakkar.