The Nightmare Cat (final version)

FINALLY he looks more like I always imagined him. Just a skinny black, ugly cat with big yellow and red eyes. With some random black smoke flying around him. And unnaturally wide, creepy, ironic smile on his face.

He's literally just a monster from nightmares who came to life after someone was killed in their sleep. He was some kind of ghost - like entity at first, but decided to change into a black cat soon. He actually didn't like this form at first, because he just became small and rather weak animal, but had no choice. He had no energy to change into anything bigger and stronger. Later, when he learn more about humans (and started to think about them as stupid and weak creatures) he started to even like his animal form. Just because nobody would even suspect, that a cat is the reason why their life was completely ruined.
He had no name at first, but decided to name himself Nightmare Cat later, just because he thought, that he deserve a name like any other living creatures.
He actually has no other goal than haunting people, causing a horrible nightmares, ruining their lifes and causing a lot of chaos and pain everywhere he goes. Nightmare does that for few reasons. Firstly, he feeds of negative emotions, mostly fear. It gives him more energy. And second, he hates humans, just because they were created as the "real" living creatures, while he was just a monster that existed only in a dream, never meant to be actually alive. The reasons of all his actions are just hunger and hatred.
Nightmare is a cowardly egoist, who lacks most of the feelings, just because he's an "incomplete" being. At the same time he's smart and cunnin. He's able to easily manipulate a lot of people. He sees humans as stupid, weak creatures who for some reasons were lucky enough to be truly alive (and he finds that very unfair, because he wasn't).
He had a power to cause nightmares and hallucinations. Sometimes is able to read some people's minds, he's doing that mostly to find out what they fear the most and use it against them. He basically just messes with people's mind until they go insane, sometimes causing them to hurt other people around them too. He isn't physically strong (well, it's just a skinny cat), and it's possible to hurt him. He knows that and most likely would just run away as quickly as possible when he realize that he's in danger. Or just change into a cloud of black smoke and disappear.

So, basically it's just a little evil thing that like to ruin people's lifes.

I actually have no idea why I created this cat and when I did it. I know, that he's one of my oldest characters, but I don't know what inspired me. Some time ago I just randomly thought, that a cat who turns to be an evil little creature torturing others will be a good idea, so I created him. Maybe. Or maybe not. But I like this character.

Again, stupidly long description is stupidly long. I'm sorry for possible errors, I'm still not good at English.

Also, I have no idea what this background is.