The Krogan are a fictional extraterrestrial humanoid species in the Mass Effect multimedia franchise developed by BioWare and published by Electronic Arts.

The Krogan are typically depicted as large reptilian bipedal humanoids who are physically tenacious, favor mercenary work, and thrive on conflict and violence.

The storyline has received a very positive critical reception and is praised for its moral complexity and nuanced writing, in particular for its effectiveness as a plot device to create friction between alien species as well as a method to develop several characters of the series.

Within the series, the Krogan are described as having warred over dwindling habitable land on Tuchanka thousands of years before the events of the Mass Effect trilogy.

[3] Once hailed as the saviors of the galaxy from the Rachni, their role at the center of the Citadel military has been replaced by the Turians, and are a shadow of their former prominence by the events of the original trilogy.

[5] The team faced limitations when texturing and preparing the Krogan character model for inclusion into the game as it still had to fit into a humanoid skeleton for animation purposes, which results in the deprecation of some early concept of large, apelike creatures.

[6] One of the enemy types introduced in Mass Effect 3 are brutes, designed as a repulsive synthesis of the body of a Krogan and the head of a Turian; the homeworlds of both species are closely linked in the invasion plan of the Reapers within the narrative.

[13] Similar to a newborn baby's skull with soft bones, a young Krogan's crest consists of many smaller segments that have yet to form into a solid plate.

[1] Female Krogan are rarely seen outside of the few Krogan-dominated worlds, where they primarily live in powerful, fiercely defended all-female clans that focus on the breeding of each meager new generation.

[1] The Krogan's slow decline due to genetically engineered impotence with the possibility of an inevitable extinction, lead to many individuals hardening their personalities and becoming self-centered.

[6] Tuchanka's surface was not always covered in bombardment craters, radioactive rubble, choking ash, salt flats, and alkaline seas, as it was teeming with life thousands of years before the events of the trilogy, where thick jungles of tree-analogues and highly competitive fauna grew in fierce abundance under the searing heat of its sun Aralakh.

[6] Notable wildlife native to Tuchanka include the dog-like varren, crab-like klixen and giant carnivorous subterranean sandworms known as thresher maws.

[14] One notable creature is Kalros, "the mother of all thresher maws" who plays a significant role in the spiritual beliefs of Krogan society as well as repelling the Reaper invasion of Tuchanka.

[6] The architectural style of the ancient ruins are based on the work of Frank Lloyd Wright, over which a veneer of Krogan aesthetics is placed to project a more brutal nature.

[6] Minor battle damage and sparse foliage dot seen all over the ruins imply that even in the face of mass destruction, life has a dim and fragile hope of persisting.

[6] Krogan characters are featured prominently in several Mass Effect media including novels, comics and an animated film where they are usually depicted as mercenaries and often assume antagonistic roles.

The first Mass Effect game provides a comprehensive background for the Krogan Genophage storyline within in-game dialogue and codex entries, and introduces Urdnot Wrex, an agent of the Shadow Broker who joins the crew of the SSV Normandy to pursue the rogue Turian Spectre Saren Arterius.

If Shepard successfully convinces him to stand down and cooperate with the team's mission to destroy Saren's base, he will return in later sequels and eventually become a leader of the Krogan people.

After meeting with Primarch Victus, leader of the Turian Hierarchy, he pledges support to Shepard on the condition that the Krogan help defend their homeworld, Palaven.

Taking a cue from Mordin's prior work on the Genophage, the Krogan that have participated in the Andromeda Initiative have undergone gene therapy while in cryosleep and managed to improve the viability of their offspring by a small, but significant, percentage.

[15] The Krogan are featured as a themed skin for Anthem player characters, released on November 7, 2019 in commemoration of "N7 Day", an informal celebration of the Mass Effect franchise observed annually.

[21] Evan Narcisse drew parallels between the exploitation of the Krogan and real world history, such as the Buffalo Soldiers, the Tuskegee experiments, as well as American and Soviet strategies of propping up despotic proxy regimes during the Cold War.

Look at the way Mass Effect meditates on power struggles throughout history and what you see is a cyclical scenario of races being allowed to proliferate as long as they serve the needs of the ruling class, only to be culled later when things get ugly.

To him, the mission's best aspect is that there is no clear ideal outcome, and called it "a masterpiece full of character moments" and the culmination of storylines involving the Krogan Genophage which had been building since the first game.

[9] Sebastian Alvarado from Kotaku said the storyline challenges players with necessary moral dilemmas and to be accountable for their actions, and serves an "ugly reminder of human history in the early 20th century where several countries practiced forced sterilization, often as part of a eugenics program.

[23] Narcisse noted that Wrex's dialogue about his people's situation in the original Mass Effect reminded him of the plight of Native Americans, and he pointed to the land struggles faced by the "remnants of the Sioux, Coeur d'Alene and Seminole nations" as an example.