Varren

From Mass Effect Wiki

Varren are omnivores with a preference for living prey. Originally native to the krogan homeworld of Tuchanka, they are, like most life from Tuchanka, savage, clannish, and consummate survivors. They are pack hunters when vulnerable prey is readily available and become scavengers when outnumbered or outclassed.

Their supreme adaptability, vicious demeanor, and rapid breeding cycle have made them ubiquitous and dangerous pests on many worlds. Virtually everywhere the krogan have been, varren infestations have followed, wreaking havoc with the native ecology.

The krogan have had a love-hate relationship with varren for millennia, alternately fighting them for territory and embracing them as treasured companions. To this day, krogan -- and some other species, including batarians -- raise them as beasts of war. A common subgenus of varren has metallic silver scales, leading to the rather unusual nickname 'fishdogs'.

Varren thrive on many worlds and in various environments, including the Prothean ruins on Feros. Humans, at least, are capable of consuming and drawing sustenance from varren meat. Commander Shepard is asked to kill a rabid alpha varren in order to permit the Zhu's Hope colonists to hunt the remaining varren. Davin Reynolds didn't just see the animals as a convenient larder, either. Apparently varren are so vicious they'll even take on the geth.

Spoiler warning: plot and / or ending details follow.

The batarians who attacked Asteroid X57 in Bring Down the Sky set packs of varren on the engineers there (not to mention Shepard and the squad). Simon Atwell hated the sight of them, claiming varren don't always wait for someone to be dead before they start eating.

One of the varren alongside Balak displays jaw articulation similar to that of a snake, suggesting that varren are capable of swallowing prey whole.