[[Human|Humans]] are a murderous lot.  With just four Humans on the planet, back just after Adam & Company strolled out of Eden, the ultimate vacation-gone-too-long, already the planet was too crowded.  So the first post-Eden crime was a fratricide, and that has set the tone for Human interactions ever since.  Poor Abel probably never saw it coming.

Of course, Humans have a history of blaming the consequences of their actions on others((Cf. politics.)) and for this reason they invented 'evil,' defining it as a vague outside force that causes their plans and '[[good]] intentions'((Cf. greed.)) to fail.  Evil is often confused with mischief, [[chaos]], or the grander acts of mayhem, but it can be distinguished from these by the way participants in the acts either invoke an outside force((Eg. 'We must oppose the forces of evil,' and other statements made by greedy sonuvabitches trying to claim their power grab is in some way more honorable than the opposing sonuvabitches'.)) or claim to have internalized that outside force as a source of authority.((Eg. 'I am __evil__, just plain __//evil//__.'  Cf. politics.))

Note:  As a [[Human]] moral construct, the concept of 'evil' does not mean much to [[kittymorph|Kittymorphs]], [[Robot|Robots]], or [[Jokers]].  It's not that they cannot grasp the concept((Cf. The Only Official Way to make clam chowder.  No [[Kittymorph]], [[Robot]], or [[Jokers|Joker]] will ever be able to properly prepare this [[Human]] delicacy.)) - it's just that they're too busy causing mayhem to care.