A hellhound is a type of canine mechanoid native to the planet Cybertron. It possesses considerable battlefield prowess and is at least semi-domesticated in service to Decepticon hunting parties.
It is described as 'soulless.'
Marvel UK comics
Snarler and the Mayhem Attack Squad set a hellhound loose in Dallas, Texas to run amok, hoping to smoke out the Survivors. Instead it turned up the rogue Decepticon Carnivac, who was grateful for a target to vent his frustrations on.