Mad Dog was created by Suicide Squad writer Adam Glass and artist Cliff Richards.
Mad Dog appears in Suicide Squad #3 attacking squad members Deadshot, El Diablo and Black Spider. Deadshot identifies him as a bounty hunter after "the package," which is also the object of the Suicide Squads mission in the Astrodome.
While using thermal vision on his mask to see through smoke, Mad Dog shoots Black Spider in the chest. Before he can fire anymore shots and steal the Squad's package, Harley Quinn releases gas into the room to prevent further gunfire. This allows the Squad to leave unharmed.
Mad Dog and his team find Deadshot and Harley at their hideout and chase them inside. Harley has once again turned on the gas to prevent any gunfire inside the hideout. All parties evacuate the building which explodes shortly after. From here, Mad Dog retreats into the nearby forest.
When in the forest, Mad Dog runs into Suicide Squad member, King Shark, who has been hiding out. Upon arriving at the helicopter for evacuation, King Shark is wearing a necklace that everyone immediately recognizes to have belonged to Mad Dog. When asked about it, King Shark says, "Found it."
Although, it is implied Mad Dog had passed, he would later return in Suicide Squad: War Crimes #1, where he would join the Squad for a mission. In a fight with Strikeforce Europa, Mad Dog was injured. Captain Boomerang left him for dead as the rest of the Squad escaped. Boomerang pushes Mad Dog from the moving van, reminiscent of what he did to Mindboggler in the debut issue of Suicide Squad. Amanda Waller detonated the bomb in his head as Strikeforce Europa's Guerrieora was about to kill him.