Origin: StarCraft

StarCraft and Korea go together like waffles and whipped cream, so it's no surprise that a few Koreanisms made their way into gaming vernacular.

Translated, "kekekeke" is the Korean equivalent to the English "lololol" and was confused by Western players as an imitation of the sound zerglings make when attacking.

The Korean laughter abbreviation became recognized as a Zerg battle cry and has since been misappropriated to images of all sorts of large armies taking an objective by force of numbers.