A gathering of deviants who find pleasure in viewing the darker side of anime characters, be it male or female.
To qualify for Psycho-Moe, the behaviour must be self-induced and not due to external control factors. So for example, Princess Euphemia from the anime series, "Code Geass" does not qualify for Psycho-Moe as she was being mind-controlled by another person.
Psycho-Moe generally comes in two flavours. The common type is one we are all familiar with, where the subject in question suffers an Emo-Facial Distortion and goes visibly batshit-insane. The poster-girl for this type is Kaede Fuyou from the anime series, "Shuffle!"
The second type is not frequently seen, but can be far more sinister, where the subject in questions retains his/her composure but performs murderous action(s) that no sane person will ever do. The classic case-study for this type is Asakura Ryoko from the anime series, "The Melancholy of Haruhi Suzumiya".
There is also the Out-of-Context(OOC) Psycho-Moe where fans impose their fantasy onto a character and foster Psycho-Moe where there was not any in the first place. This can often lead to humorous results.
For any of the pictures posted here by me, feel free to PM me for the original sizes.