Zerg  

ZAM Network Wikibase™ Dictionary

Common gamer slang, a zerg is just charging the target and, if you die, just revive and charge back in as fast as you can. Zerging is most useful when the target is near your revive/respawn point.

For those that care, the term zerg predates the "Zerglings" in StarCraft, but they epitomize the technique, overbearing their targets under sheer weight of numbers.

Frequently, the term is used derogatorily to describe an attack with no technique or finesse.