The Swarm is a nickname given to the deadly Piranha-Leeches of Planet Wargod's subterranean Ichor Crystal mines. The Leeches have the strange ability to "swim" through the air, using Mars' lighter gravity and small air sacks within their bodies to stay aloft. They move extremely quickly and in groups of fifty to 200 Leeches, and, as their name suggests, they are flesh eaters. A single swarm of Leeches is able to pierce through body armor, burrow under the victim's skin, and eat their way out. What's worse is that the Leeches evolved through basking in Ichor radiation, so if a human is only bit by a single Leech the side effects of Ichor radiation could still take place.