Lunatics

During the events of Batman: Arkham Asylum, the most hardcore and utterly deranged of the many grim cases at the Asylum were let out of their cells by Harley Quinn on the orders of The Joker. It is worth noting that, after doing this, one of Joker's many taunting messages over the public address system included instructions for his people to put these lunatics down on sight. He seems to have ordered their release strictly to harass Batman, but even so, was wary of them, as their madness may be to him what his is to most ordinary people.

These are true lunatics, with no grand designs or iconic motifs, only purest insanity driving them. They are incapable of coherent speech and will instantly attack anything or anyone. Only complete unconsciousness or death will keep them from attacking in an all-out frenzy that is capable of badly injuring even Batman. Facing more than one in the same area can be difficult, and they are the main reason that the Insane Night Map combat challenge can only be endured, never truly beaten.

The Lunatics cannot truly be described as henchmen; the Joker has no control over them and it is at least careful of them; it is possible that releasing them was a contigency, rather than part of whatever made up Joker's original plans, as conversations between Joker and Harley indicate that Batman is progressing faster than Joker cares for. They seem to embody the deservedly nightmarish reputation Arkham has earned, their very existence an assault on all the senses, perhaps not evil, but very certainly badly lost souls still capable of horrific acts as the pain in their minds pushes them to inflict pain and death on others. Notably, they are the only lethal obstacle besides Ivy's spores and electric screens that can still attack Batman even after Joker's final defeat.

Their appearances prior to incarceration are lost; Their appearances in the game are almost all uniform, madness plus the necessities of extreme high security confinement leaving them all looking bald, hunched over and skinny, with their insanity-driven strength compensating for their lack of bulk. At least one Blackgate henchman openly questioned Joker's decision to release the Lunatics, and in this instance, his fellows didn't warn or hush him.