When a person's emotions go from extreme high to extreme low in a short period of time. This variation can sometimes be scary, irritating, or even annoying!! >_<
A crazyguy who abuses power, pretends to be loaded, throws people through windows, sues people for no damn reason, and then tells them how much he likes them!
That moody is one unhinged mug, the took a bat to my car and then asked if I wanted ice cream!