Archeon/Chernobyl's Remains

The Chernobyl's Remains is a weapon you can buy from the Arms Dealer after killing the Eater of Worlds or Brain of Cthulhu. Chernobyl's Remains shoots a projectile that is similar to the Chlorophyte Bullet, but doesn't have homing and instead inflicts Corrosion onto enemies.

Trivia
The projectile that the Chernobyl's Remains shoots is a reference to the Borderlands Corrosion element.

The gun's sprite was supposed to be a handgun, but because of some miscommunication it turned out to be an Assault rifle instead.