Back from Call of Duty: Black Ops III is the Marshal, a double barrel pistol and a shotgun box. Starting at the beginning of Season 5 for Call of Duty: Black Ops Cold War and Warzone, players can unlock the Marshal as a new secondary weapon via weapon unlock challenges, either via Cold War multiplayer, Warzone or Cold War Zombies. Alternatively, you can purchase a version of the Marshal's blueprint in the in-game store, although you'll still need to complete any of the challenges for the basic version of the weapon.
Related: How to Unlock EM2 and TEC-9 in Call of Duty: Black Ops Cold War and Warzone
Multiplayer and Warzone Unlock Challenge
The Black Ops Cold War and Warzone multiplayer challenge to unlock the marshal reads: "Using guns, get a headshot kill in 15 different matches completed." Guns aren't the usual type of gun you'd think you're going to get headshots with, but it's very doable. The full-auto AMP63 might be the way to go, or perhaps the mighty Magnum. Remember that the challenge requires you to perform a headshot with the gun in “different games”, which means that getting more than one headshot with your gun in a single match will only count as a notch for the challenge.
Zombie Unlock Challenge
You can also unlock the Marshal through a zombie-specific weapon challenge - the challenge reads: "Using guns, kill 30 disciples while they have at least 5 zombies under their control." The disciples appear to Mauer der Toten, taking control and empowering common zombies. He looks for those who attract undead groups and aims at them.
