Intervention

The Intervention is a sniper rifle that appears in some fanon maps.

A Darker Shade of White
The DP-28 appears in A Darker Shade of White as a Mystery Box weapon.

Effectiveness
It is one of the most effective LMGs in Zombies. It possesses a power similar to others, but has a higher mobility. It's only comparable con is a smaller clip size, but it comes near the same ammo count.

Bolter
When Pack-a-Punched it becomes the Bolter. It gets a damage boost, less sway and is also more accurate when hip-firing. It also comes with more ammo.

Popper
When Super Punched it becomes the Popper. It gets another damage boost, even less sway, even more hip-fire accuracy. You also gain a variable scope, a larger clip and more ammo.