Joker's harpoon toy gun (more commonly known as the "'BANG' flag gun") appears as an ordinary gun at first. When
fired, rather than a bullet, it pops out a flag reading "BANG!". However, after the trigger is pulled again, the flag itself is shot out the barrel and impails the target.
In DC Universe Online, the gun is a pre-order trinket called "Joker's Trick Pistol".
- In the edited version of "Batman Beyond: Return of the Joker", the second trigger releases a blast of Joker Venom, as the edited version was censored to include less violence.
- In the story "Dreadful Birthday, Dear Joker!" (Batman #321), the flag reads "BANG YOU'RE DEAD!" rather than just "BANG!"
- "The Killing Joke" had an "empty" version (the flag read "CLICK CLICK CLICK")