This is King, a Varren. If you are not familiar with Varren, then you should SO stop reading this and go play the mass effect games right. Now. Or you can check this out: http://masseffect.wikia.com/wiki/Varren
King is a fancy breed Varren. Their colors were developed through selective breeding for showing, and the various varren morphs are coveted by varren lovers across the galaxy. It is also very expensive to purchase such a coloration of varren, costing more than even the uncommon striped varieties. Most folks who want a pet varren simply purchase one of the prolific red or blue breeds.
King was born from champion bloodlines and is an extremely valuable varren, but he is very high energy, something that his original owner was unprepared to deal with. They simply wanted an expensive living trophy. After his pent up energy resulted in major damage to the interior of his original home and began to make him more aggressive and domineering, King was tossed out. Not adept at living on his own like real wild Varren, he did not fare well. His colors blanched, his weight dropped, and he became increasingly distressed without something to socialize with. His current owner Felroan (https://www.furaffinity.net/view/4722317/ ) found him cowering in a marketplace on a usual trip to replenish supplies.
King is now a healthy, active working Varren who assists in combat on the field, which is excellent for expending his otherwise destructive energy. He is spoiled rotten with treats and is rather portly as a result, but a large amount of his mass is muscle, considering this is an animal that has to be able to run fast and hit hard. He functions as both a weapon, pack mule, lovable oaf dog, and comic relief aboard The Salty Wench. While not everyone on board is a fan of him, King is still a valuable member of the Maw Aces.