Antarctica is the coldest and most southerly of the five continents, the only one that doesn't have any actual countries in it, and the only one you never had "native" (pre-colonial) ancestors on. Contrary to popular belief, Antarctica has two C's in its name, not one. It is a landmass, coated almost entirely in a thick (but thinning) sheet of ice. It is home to several scientific research stations, and not a whole lot else, due to the bad climate. Antarctica is much smaller than it looks world maps due to distortion. Since the Earth is a sphere and not a rectangle, the poles are stretched out on rectangular maps, distorting the portrayal of landmasses found there. Antarctica is the second smallest continent, not a gigantic ice-monster that takes up a quarter of the planet.
Antarcticans refer to those from people born in Antarctica.
Over 10 people, since the 1970's, have been born in Antarctica. These are the only racially pure people with exactly 100% from a single icy continent (void everyone being African) as they are "aboriginal" since they were the first group of people born there. Everyone alive had Human ancestors on any and all of six Continents at some time thousands of years back, excluding Antarctica. This makes Antarctica the only continent you aren't at all indigenous to, unless you are one of, or a descendent of, an Antarctican. Thus Antarctican is the most exotic ethnicity adaptably.
Universal ancestry on the normal 6 continents: *