It is commonly accepted that Batman is one of several superheroes that will not take a life during his crimefighting crusade. This has not always been the case, as his earliest appearances saw the Dark Knight kill many of his opponents in a callous manner that is almost never seen these days.
Despite having a rather staunch no-kill rule in more modern incarnations of the character, there have been instances where the Caped Crusader broke his oath, either out of desperation or out of sheer malice.
For starters, most of his cinematic adaptations (aside from his most recent outing, The Batman) have seen Gotham's protector display a chilling predisposition to murder. Beyond this, various alternate reality versions and even the main timeline incarnation have resorted to lethal methods to achieve his goals.
This is undeniably terrifying as Bruce Wayne is one of the most formidable beings in the DC Universe, powered or otherwise. His near-unmatched prowess in combat, strategy and access to dangerous items and weapons makes him an intimidating opponent - even more so when he is going for the kill.
From creatures of the night to god-like beings and even his heroic counterparts, there is no denying that Gotham is fortunate to have a Batman who exercises restraint (for the most part).
10. The Joker - JLA: The Nail
Few villains strike fear in the heart of most heroes, villains and ordinary DC citizens such as the Joker.
The Clown Prince of Crime has dealt Batman many humbling defeats over the years, and his reign of terror has not only affected Gotham but also the entire DC Universe at large. Among others, the volatile villain has been responsible for the deaths of Jason Todd and Sarah Essen as well as Barbara Gordon's paralysis.
Unsurprisingly, many fans have wondered why Batman spared his nemesis despite all the devastation he wrought over the years, and 2001's Elseworlds story, JLA: The Nail, realises what would happen if the Gotham Knight decided to put an end to the Joker's cruelty.
In this Superman-less reality, the Joker orchestrates a massive breakout at Arkham Asylum, and in true Joker fashion, kills Batgirl and Robin in the process. A vengeful and grieving Batman then savagely beats the criminal and snaps his neck on live television.
It was later revealed that the Joker intentionally provoked his foe into attacking him, knowing it would tarnish the Justice League's already shaky reputation.