The Clone Gun is a ranged weapon in Spelunky 2. It is given to the player after successfully completing the stars challenge in the Tide Pool ran by Tun. It requires the player to light every torch within the room, upon which the Clone Gun will be found in between the two forcefields, where the clover is placed.
The clone gun has the ability to duplicate any object it shoots, however it will break after 3 uses. This makes it an exceptionally strong tool, allowing the player to duplicate crates, items themselves, damsels, or even enemies.
The clone gun has a special interaction with Excalibur. When used on the weapon, it will spawn a broken sword. While the broken sword acts the same in terms of still being usable as a weapon, its use beyond that is unknown.
Using it on a laser wall to reflect the shot back at yourself will grant you a clone, which is just a Hired Hand with the same appearance you are using.
If you use it on the Golden Idol in the Ice Caves, nothing happens, but if multiple Idols are moved/whipped, then multiple Boulders will fall, instead of 1. (For example, Moving/Whipping 2 Idols will spawn 2 Boulders, 3 = 3 Boulders, and 4 = 4 Boulders.