|“||Good evening, residents of Joker Asylum. Some of our...crazier guests crashed the party early. And when I say crazy, I mean real psycho. Word of warning. If anyone sees a dribbling fool barking at the moon or maybe just purring like a kitten, do you're civic duty. Walk up to them. Put your arm around them. Show them that you care before you wring their necks.||„|
They were completely insane inmates at Arkham Asylum who were imprisoned at the Penitentary on the Island. While not evil, they are lost souls, also they attack anyone or anything they see, making them the most insane and dangerous inmates at the Island. The only way to stop them is to knock them out or kill them.
During Joker's take over on Arkham Asylum, Harley Quinn release the Lunatics in an attempt to stop Batman from progressing. Although, the Dark Knight managed to take them all down easily. Joker then ordered his men to kill Lunatics on sight because their too dangerous to let live and cannot be controlled at all.
Its later revealed that the Lunatics, are in fact failed test subjects of Hugo Strange's in his attempts to perfect brainwashing, using technology he stole from the Mad Hatter. When it became clear the experiment had failed and severaly damaged there minds in the procees, he had them lobotomised, leaving them beyond repair and hid them in the asylum as patients, to cover up his secret opperations. He had several of the ones who managed to survive the Joker's assult given to the Penguin who used them for target practice.