A very short person who will always make up things about his life because his insecurities get the better of him. So short that he speaks big and talk words to compensate for his midget height. Great with sex as a Niko can slip into any small objects during intercourse.
You man I was walking down my 'hood when all of a sudden some Niko jumped out at me with an Airsoft gun and tried to threaten me with it. I just jumped over it and went on my merry way.