GullinburstiSus chthonii

Gullinbursti or just Bursti (Sus chthonii, "chthonian pig," in reference to their planet's namesake) are the second-most populous species on Tartarus and make up the majority of the aristocracy. They evolved from Humi pigs. All Tartareans are ruled by the negligent king, Helhest, and the royal family of Sleipnir. 

Upper class Bursti are prone to lavish and overindulgence, preferring to spend their time in endless revelry. They have a strained relationship with most other Tartareans because of this—even their fellow elite. They are especially despised by the Gullinkambi—whom the Bursti derisively call Fjalar instead—and the Auðumbla, whom suffer beneath their boot. By the (rightfully) scournful common folk, the aristrocrats are referred to as Hogwash and a litany of other pig-related terms. ("Cow, pig," etc. are usually insults in and of themselves.) 

The (noble; most are, but not all) Bursti that have otherwise "defected" from the status quo are referred to as the Hildisvíni, a distinction they made to separate themselves from the royalists. Hildisvíni, much like the Kambi, support and/or work alongside the Umblan revolutionaries, with many forsaking their ranks altogether. Noble or otherwise, the royalists very much target and retaliate against known Hildisvíni; the former has too much insight, and the latter are deemed traitors (with "traitor" and words like it being regularly flung their way by the elite.)

Outside the worst of the aristocracy, Bursti are hearty, highly social, and hospitable. They're the type to celebrate every happiness, invite anyone they can to a party, pay for everyone's meals, etc. While still notorious for their merrymaking, it is viewed in a far more favorable light. Many famous chefs—or what could even qualify as a chef in a place like Tartarus—are Bursti who simply have a passion for the happiness that comes with good food and full stomach.

Bursti can range from appearing pig-like to boar-like, with the former being far more common. They are omnivorous.