The Wave Gun is a Wonder Weapon that is featured in the zombie level Moon. It causes zombies to cough up blood, slowly expand while floating away, and then explode into red mist. It can also be taken apart and Dual Wielded, where it becomes the Zap Gun Dual Wield.
When Pack-a-Punched, the Dual Wielded version becomes Porter's X2 Zap Gun, and the combined version becomes the Max Wave Gun.
The Wave Gun will be able to "cook" the zombies from the inside out, causing the zombies to expand slowly, then taking the zombie off the ground and suddenly explodes. The Wave Gun has two parts, and can cook the zombies if they are connected, or can electrocute the zombies if Dual Wielded (Dual Wield Wave gun is like the entire but broken in half and with one part per hand and more ammo).