Crazy is a state a character can be in. It's different than the typical "crazy" or "insane", but still affects the character's thinking and actions, which makes them appear crazy. (This state may or may not be mental-related.)
Craziness can cause a character to act and think differently, sometimes even against their will. On some occasions, Craziness can even cause a character to act almost evil; it possibly being a gateway to a character's Dark-Self, sometimes.
Characters with Craziness almost always look the same to their former counterpart, but usually will have widened eyes with narrowed irises and ringed, little, or almost no pupils. Most of the time, they will also have a smirking or laughing expression, or no expression at all.
Craziness can be caused by many things, but it is usually caused by a character's triggers to an extreme level, or extremely stressful situation(s).