To make oneself at home in a friend's place and lay waste there.
Originally from the game Starcraft where Zerg are an alien playable race who tend to expand through the map using their creep.
Mathieu : Man remember that LAN in Cyril's place ?
Yannick : Hell yeah we totally
Zerged the place in a minute !
Mathieu : That was before pooping a creep tumor in his bedroom !