The Joker is inexorably connected to Batman. Most people can't imagine one without the other, and they have been at each other's throats for over 80 years. Depending on the canon, they have tortured each other, taunted each other, and even killed each other.
The Joker, however, is a very generous villain in that he has lots of hatred to go around, and not just for the other heroes he occasionally crosses paths with.
During his career, the Clown Prince of Crime has butted heads with almost every other major villain in the DC universe. The Joker's massive ego, twisted outlook on reality, immense resources, and need to prove himself right make him a bad guy who doesn't like to go gently into that good night.
On the contrary, he takes immense pride and joy in embarrassing other villains and will often go to great lengths to prove that he is the superior psychopath, laying plans that sometimes take years to come to fruition.
And sometimes, he just shoots other villains in the face. Not subtle, but it sends a message.
Knowing that he hates to lose, here are some of the times that The Joker humiliated other DC villains...
10. Maxie Zeus
Taking on the Joker as another villain is an arduous task. If you're used to taking on someone from the Batman Family, who fights with logic and reason (despite being dressed in spandex), you're going to have a hell of a time wrapping your head around how to slug it out with Joker.
Maxie Zeus should have heeded this lesson.
At a time when the two villains were fighting for leadership of the criminal underground in Gotham, an attempt by Zeus to talk Joker into surrendering goes horribly off the rails.
Zeus, who is selling a drug that is a combination of Joker Venom and ecstasy, tells Joker if he doesn't give up their quarrel and let him take over, he'll 'crush him like a bug.'
In return, the Joker, who not only doesn't appreciate the threat but is upset that Maxie has co-opted his Joker Venom to make his own designer drug, attacks not Maxie, but his nephew.
By blowing up the kid and his entire school.
Killing kids is nothing new for the Joker (see Jason Todd) but even for him this seems a bit of overkill. It did, however, force Maxie to surrender, which is all Joker wanted in the first place.