Etchy, one of the largest residents of Teras Terrace, is a living house, or at least a living creature that looks like a house. Etchy's origins are mysterious; the fact that he speaks with a thick Spanish accent may or may not provide a clue. In any case, Etchy derives nourishment by somehow siphoning energy, and indeed even some mass, from those living within. While the amounts it consumes are insignificant for a short exposure, living for a prolonged amount of time within would prove very dangerous. For this reason, when Etchy is unoccupied Terrace residents (or rather households) are chosen by lot to take turns living in him for one week. Etchy also serves as guest housing for visitors and unexpected new arrivals... provided, again, that they don't stay in him longer than a week or so.
While Etchy is for the most part stationary, occasionally he somehow gets loose from the Terrace, disappearing from his usual spot and appearing somewhere else in the world. When this happens, he has to be found and brought back before he poses a threat to hapless inhabitants... or to Pretorius Technologies' secrets.