|Mass Effect 2|
Drell are omnivorous reptile-like humanoids with an average life span of 85 galactic standard years. They give live birth to their young, who are capable of eating solid food from the moment they are born. Drell appearance is very similar to asari and humans, but their muscle tissue is slightly denser than that of humans, giving them a wiry strength. Many of their more reptilian features are concealed, like a three-chambered heart with a muscular ridge that is capable of shunting oxygenated or deoxygenated blood as needed.
One unique characteristic, however, is the hyoid bone in their throats, which allows them to inflate their throats and produce vocal sounds outside of the human range. Would-be assassins have noted that these two features make drell extremely hard to strangle or suffocate.
Because the drell ancestors emerged from arid, rocky deserts, the humid, ocean-covered hanar homeworld of Kahje proved tolerable only when the drell stayed inside a climate-controlled dome city. Due to this huge disparity in the two species' homeworld environments, the leading cause of death among drells on Kahje is a bacterial lung disease called Kepral's Syndrome.
Within a generation of the drell's arrival on the planet, the disease had become resistant to hanar antibiotics and other advanced treatments. Once an infection settles in, death is slow but imminent. Transplants may buy time, but as the infection spreads to other major organs there comes a point of diminishing returns and eventual system failure.