Eraser and Pen are characters from Battle for Dream Island, the animated web series built around competing objects, and this short exchange has become a favourite reaction clip in fan edits and meme videos. Its appeal is simple: the drawn-out word captures the exact feeling of hearing that something costs nothing, so editors reuse it whenever a free reward, unexpected gift or too-good-to-be-true deal appears. Like other excited reaction sounds, it spreads mainly through short-form edits, where its brevity and cartoon energy make it easy to drop into almost any funny moment.