In the Mass Effect games, Commander Shepard meets aliens of all different races, and that includes the Volus race. They're not intimidating, but they're certainly important.
It is the Turians who police the galaxy with patrolling fleets, the Salarians who invent scientific marvels and the Asari who preserve high culture. These are all noble pursuits, but they require money, and the world of finances is central to the Volus race. These petite aliens can make coins dance.
Humble Builders Of The Economy
The Volus hail from a distant world named Irune, which lays outside its star's habitable zone. It can support life because of its dense methane atmosphere, and thus the Volus have high-pressure bodies and breathe methane. Whenever they board spaceships or other worlds, they must wear pressurized body suits at all times, and this is the default appearance that other alien races see. The Volus are stout, rather short compared to most bipedal aliens and have minimal martial prowess. They do have modest fleets and build weapons, but overall they are not known for any significant military actions.
Instead, the Volus are master merchants and business leaders, and this stems from their highly fluid and fragmented culture back home on Irune. As opposed to conservative races like the Asari, Turians and Elcor, the Volus live in family packs that constantly exchange members and territory for gain. Once a clan becomes large enough, it splits up again. No one is complacent on Irune; they have to keep playing the game or risk falling behind. In fact, the Volus do not have family names, since being born into a family and having its name would suggest that the parents own the children, a concept the Volus reject. Volus instead have two familiar names, which tend to be rather short and have hard sounds. Examples include Barla Von, Pitne For, Niftu Cal and Din Korlack.
The Volus On The Galactic Stage
The galactic stage is a diverse one, and all advanced races need banks and currency to operate. Having so many civilizations lumped together creates a maze of finances, but the Volus race single-handedly created a standardized galactic economy that keeps money flowing smoothly and fairly. Today, Volus are often business leaders, bankers, credit unions employees, financial advisors and business leaders, using their natural affinity for trade and economics to their advantage.
In particular, the Volus are a client race of the Turians: in exchange for the Turian Hierarchy's military protection, the Volus lend the Turians economic favors and trade rights. Thus, no one dares to attack the Volus. And, as thanks for their hard work building the galactic economy, the Volus have expanded their territory a great deal in the last few centuries, about tenfold according to the Presidium's Elcor ambassador. The Volus lack a seat on the Council, however, a fact that grates on the Volus ambassador Din Korlack.
However, not all Volus are as noble as their role in the galaxy would suggest. For the most part, the Volus are cooperative and honest in their dealings with other races, but some may be ruthless, shady or downright criminal in their actions. The Volus are a pragmatic and "it's only business" sort of race, and some individual Volus are exploitative that way. Pitne For, a Volus trader found on Ilium, traded faulty Red Sand (a biotic-boosting drug) to an Eclipse gang there, and he was caught trying to swindle them. He turns to Shepard to help him avoid a brutal retaliatory action, lending him the passcard needed to raid the Eclipse base. What is more, Pitne's business partner, Niftu Cal, was stranded, and Pitne was perfectly willing to abandon him and flee Ilium entirely. The only reason Pitne didn't actually leave was the Ilium police keeping him in custody for questioning.
Barla Von is one of the first named Volus whom Commander Shepard meets, operating on the Citadel's Presidium. He's not here to run a credit union or maintain stock exchanges, however; he is a prominent agent of the Shadow Broker. Barla Von is probably only second to the Broker in terms of collecting and trading secrets, and he immediately knew who Shepard was. Barla Von is polite but ruthless, and he explains how the insidious Shadow Broker operates without making any apology for his role in the Broker's vicious game of trading secrets. Barla Von says that this work has made him "very wealthy" and comfortable, and he doesn't mind trading secrets that can ruin empires or shatter businesses in the Shadow Broker's game. Whether or not Shepard objects to that is up to the player.