A trained wolfhound with an Overseer.
Exploding Hounds is a written note found in Dishonored.
Transcript[]
I've seen the harnesses you've been devising in that workshop of yours. If you plan to strap explosives to my precious hounds and make living bombs out of them, you can count me out of your plan. I'm the master of the hounds here, and without my training they'll never do as you request.
Signed,
Hound Master Warton
Location[]
It can be found in the locked workshop in the Back Yard of the Office of the High Overseer during the mission High Overseer Campbell.