(helluva Boss): Eso

In Helluva Boss , (often stylized as ESO ) is not a character, but rather a prominent background brand and easter egg appearing throughout the series. It is a parody of real-world gas station brands (specifically Esso/Exxon) and is primarily associated with the series' setting in Hell. Brand Appearance and Role

: The brand frequently appears in the background of episodes, often featuring hellish puns or crude humor on its signage, consistent with the show's "Hellaverse" world-building. Eso (Helluva Boss)

If you are referring to something other than the background brand, "ESO" is occasionally used by fans in these contexts: In Helluva Boss , (often stylized as ESO