"Me? I'm dishonest. And a dishonest man you can always trust to be dishonest. Honestly. It's the honest ones you need to worry about. Because you can never predict when they're going to do something incredibly...stupid"
The wild cards. Chaotic Neutral characters are those who do whatever they please, are led by whims, and are oftentimes incredibly mercurial. They do whatever they want, whenever they want, but are sufficiently restrained that they are not nihilists or straight-up evil. Chaotic Neutral characters may do good one moment, and then perform a roguish deed (such as stealing) the next. They may help the heroes purely on a whim, only to later aid the villains to further their own agenda, and then go back to helping the heroes again. Simply put, Chaotic Neutral characters usually can’t be counted on to be consistent. They follow their own rules and only their own, having no use for the laws and regulations of authority.
Besides the above though, there are also other Chaotic Neutral characters who are not mercurial people that do random things on a whim, but still operate outside of authority and are also too morally gray to be definitively good or evil. Examples of this would include a brutal outlaw vigilante who goes a bit too far fighting evil/crime, or a well-meaning anarchist that goes too far when fighting a corrupt authority.