The reference goes even further than that. This particular quote comes from a blue post paraphrasing "Im in ur base killin ur manz" (or the rough equivalent), meaning "I have taken roost in your home, and am systematically eliminating your teammates."

A blue post is an entry into the World of Warcraft forums that has a distinctive blue text, and is created by a Blizzard moderator.

This image cracked me up SO HARD that I couldn't type all of this out for some minutes. I keep scrolling back up and bursting out in tears. Tears of joy.