A person who slays noobs on popular video games such as Halo or Call of Duty. Often a casual gamer who kills a regualr playing nerd, referred to as a noob (Doug Marsh, Eddy Full, Fin Donaldson,Pickled Bums). The title of noobslayer is one that has been fought over for many generations.
Noobslayer: Ha, I owned you you stupid noob
Noob: Stop killing me it's unfair.
Noobslayer: I AM TEH NOOBSLAYER