Side view of the Reaper.

The Reaper is a multiplayer-only weapon introduced in the Hell Followed DLC. It's a gun that unleashes six-round bursts of Hell energy, and has a weapon modification that allows it to charge up a shot for increased damage. It was recovered directly from Hell, and unleashes tortured souls that annihilate opponents. It appears to be designed similar to the Unmaker from Doom 64.