Zilla Shotgun

 is a gun that fires a shotgun blast of bullets. It can be charged to fire the entire magazine at once, which will cause it to fire piercing, bouncing bullets.

Trivia

 * Zilla Industries is a reference to a company of the same name from the Shadow Warrior game by 3D Realms which the titular hero fights throughout the game.
 * In Shadow Warrior, the player can also use a quad shotgun.
 * The orbiting Demon Head gained through the synergy is likely a reference to one of the game's weapons, a demon head that shoots a laser out of its mouth.