Derived from the slang word "noob"
The word "noob" is often a common insult used amongst gamers and is used by those who are.. for instance a "higher level" in a game than the person whom they are insulting.
Originally noob (or newbie) was thought to translate as "inexperienced low-level player".
Like its predecessor, doob is also often used as an insult amongst gamers with the exception of noob also insulting ones IQ and means "Dumb (ignorant. mentally challenged) noob"
The word also slightly resembles a mindless human with large ears and a blank expression, occasionally containing what appears to be a nose.
Originally doob was intended to be a mockery of the word "noob" as more of an insult to the path in which modern slang words are leading current and future generations.
That dO.ob got O.ownd!!