There are few heroes who have as strict a "no killing" policy as Batman. However, that doesn't mean that the Dark Knight doesn't get angry. In fact, much of his masked persona is built around appearing to be an unending rage machine to terrorize the underworld of Gotham City and the world at large.
Even then, Batman has lost his temper on several occasions. Every once in a while, Batman becomes so angry that he cuts loose on allies and enemies alike. That brings the discussion to today's topic: 10 times that Batman lost his temper (and why). Expect spoilers for several DC stories below.
11 Batman Going After Deathstroke
Unlike most "losing their temper" moments, this story found Batman in a perpetual state of rage until he found an answer to his question. That question was: who is Damian's true father. Batman was given evidence that Slade Wilson, aka Deathstroke, may be Damian's true father.
This led to Batman going after Deathstroke, who honestly couldn't care either way. The two men battle it out across the globe while being provoked further by Talia al Ghul. Ultimately, Deathstroke and Batman had one final brawl in the Batcave before they came to an understanding.
10 Batwoman And Batman Fought Over Clayface
For a time, Batman tried to set up a Gotham-based group called the Gotham Knights. This consisted of Batman, Batwoman, Spoiler, Orphan, Red Robin, Batwing, Azrael, and a reformed Clayface. Batwoman was intended to be the leader, but it all came crashing down after the supposed death of Red Robin and Batwoman having to put Clayface down.
Clayface had been driven insane by Hugo Strange and set loose to terrorize Gotham. Clayface had been briefly calmed down, and Batwoman had one chance to use a special serum to kill Clayface. She took it. This led to Batman disbanding the team and coming to blows with Batwoman. This was escalated after Batwoman used the audio of the type of gun that killed Bruce's parents to make him flinch, but the two came to a tenuous understanding sometime after that.
9 He Viciously Beat Joker In A Death In The Family
This is a more famous breakdown on the part of Batman. The second Robin, aka Jason Todd, was kidnapped, tortured, and killed by the Joker. Afterward, Batman scoured Gotham to verify the Joker was the true cause of Jason's death — which he was — but the Joker had diplomatic immunity at the time as the ambassador from Iran (yes, for real).
However, with the help of Superman, Batman was able to expose the Joker and lay a royal beating on the Clown Prince.
8 Batman Fought Jason In Red Hood And The Penguin
Of course, Jason was later revived through a Lazarus Pit and set loose in Gotham as the new Red Hood. This led to a few duels with Batman, but Jason eventually became Batman's ally once again. However, this was tested after it appeared that the Red Hood killed the Penguin while giving a speech.
This led to another fight between Batman and Jason, where Batman brutally beat Jason and said that he should never have taken Jason in.
7 Requiem Saw Batman Go Into A Spiral
Jason wasn't the only Robin that Bruce lost, though this loss was temporary as well. Damian Wayne was killed by a clone of himself called the Heretic, and this left Batman in a spiral.
Bruce went on for weeks without taking off the Batsuit, and he was brutally dealing with any and all criminals that he encountered along the way. Ultimately, a Batman enthusiast named Harper Row was able to track down Batman and get through to him, though he did rebuff her efforts at first. Harper would later go on to become the vigilante Bluebird.
6 Guy Gardner And The JLI Witnessed Batman Punching Green Lantern
This is another famous Batman blowup. While Batman was working with the Justice League International, he attempted to assume the leadership role of the team. However, the brash loudmouth Green Lantern named Guy Gardner wanted to be the leader instead.
In response, Batman punched Guy Gardner once, knocking him out while Blue Beetle cheered on.
5 Batman And Hal Jordon Fought In Green Lantern Rebirth
This came back around on Batman though. Bruce was very skeptical of Hal Jordan when the Green Lantern was first resurrected and attempting to become a hero again. He felt that Hal hadn't adequately paid for his crimes as Parallax, and his explanations were too convenient, even if the rest of the Justice League believed Hal.
However, Hal Jordan was too busy trying to deal with Sinestro and the return of Parallax to deal with Batman's questions. Hal Jordan punched Batman while Guy Gardner cheered on. Later, Batman got Hal Jordan back for this with a right hook.
4 Zero Year Saw Batman Beat The Riddler To A Pulp
Batman's earliest outings were retconned with the New 52, with the new "first" Batman story centering around his first encounter with the Red Hood and the Riddler taking over Gotham. The Riddler cut Gotham off from the outside world and shut down all power.
It took Batman a long time to do it, but he was ultimately able to catch up to the Riddler and gave him a beating so bad that Ed Nygma was hospitalized afterward.
3 Batman Lost Patience With Joker In Death Of The Family
In a relatively recent Joker story, the Clown Prince of Crime led Batman through a house of horrors in Arkham Asylum, only to evade Batman's capture and leading the Caped Crusader back to the Batcave. All the while, the Joker was claiming to know all of Batman's secrets (which was later revealed to be true-ish) There, Joker had Nightwing, Robin, Red Robin, Batgirl, and Red Hood tied up with Alfred being controlled with Joker Toxin. Joker was threatening to kill all of the Batman's associates and nearly did.
However, the Bat-Family managed to free themselves, even if it did come down to a Joker Toxin-fueled brawl while Batman tracked down Joker and nearly beat him to death.
2 KGBeast Got Revenge For Nightwing's Memory Loss
More recently, the villain known as the KGBeast was hired by Bane to assassinate Nightwing. KGBeast failed to kill Nightwing, but his bullet still badly wounded Nightwing and caused significant memory loss. Upon waking up, Dick Grayson abandoned the mantle of Nightwing and the whole Batman Family.
KGBeast fled the country after this crime, but Batman tracked him down to the frozen tundras of northeastern Europe. Batman and KGBeast had a grudge match, and the Dark Knight brutally beat KGBeast and left him with a broken neck in the snow — but still alive.
1 City Of Bane Saw Batman Lose His Head After Alfred's Death
Finally, we have possibly the most recent case of Batman finally losing his cool with a foe. Bane killed Alfred Pennyworth at the behest of Thomas Wayne, the Batman of the Flashpoint timeline. This Thomas Wayne desperately wanted Bruce Wayne to stop being Batman and thought he could only get Bruce to quit by breaking his spirit.
Batman beat Bane, but he still had to fight Thomas, who dropped Alfred's corpse in front of him as a final attempt to break Bruce's spirit. This only enraged Bruce further, and Bruce and Thomas had a brutal brawl during which Bruce proclaimed that Thomas isn't his father anymore. Ultimately, Bruce won the fight.