Nine is a genderless, sentient mathematical species of something called an ‘Algebralien’, being a subspecies known as an Integer. Their body is a Light Greyish–Blue Color resembling the arabic numeral nine ( 𝟿 ) with their limbs having a much lighter hue of their body, They wear black sunglasses that appear to have two smooth, curvy line patterns on both lens which seemed to have a gradient color with yellowish gold on the top, white converged in the middle and blue on the bottom. They also seem to have an eye condition known as ; heterochromia, with their left iris being a pale yellow while the right one is a light blue color. Nine has an overly exaggerated 1990s or 2000s skater subculture persona, They act like they are incredibly suave and popular. They heavily lean into retro skater tropes, constantly riding a skateboard and throwing around nostalgic slang terms like "tubular," "rad," and "dude". Nine can sometimes behave immaturely and toughly while trying to hide away their insecurities, They're only ACTUALLY comfortable around their beloved spouse and would even often show their true selves. They're shown to lack basic common sense and sometimes can be a bit clumsy when skating around but they manage to stay confident and optimistic.