Krogan Warrior

The Krogan are a race of large, reptilian creatures from the harsh, arid planet of Tuchanka, home to vast deserts, and numerous dangerous predators. Like all life that survived on their homeworld, the krogan are tough, fierce, and violent. The Krogan fought amongst themselves frequently, culminating about four thousand years ago in a devastating nuclear war, in which much of the Tuchanka was reduced to a barren wasteland.

Two thousand years after the nuclear war, the salarians, another alien race, discovered the Krogan and with their help, the krogan advanced to a spacefaring civilization, aiding the salarians and turians in their war with an insectoid race known as the rachni. After the defeat of the rachni, however, the krogan began expanding, attacking turian and salarian colonies. The turians and salarians fought a bloody war with the krogan, culminating in the turians and salarians deploying a jointly developed biological weapon known as the genophage, which caused 70% of krogan births to miscarry, resulting in a rapid population decline.

If Commander Shepard chooses to, he/she will aid the krogan and a salarian scientist in curing the genophage plague, gaining the support of the krogan clans in the war against the The Reapers.