On That Day, Humanity Received a Grim Reminder is a copypasta taken from the first episode of Attack on Titan, spoken by Eren upon seeing the first colossal titan peering over the walls of his sheltered city. It has become an iconic line in the series, although there are several other translations of the line in english dubs and subs. It is most referenced in parodies in which a different, more humorous giant character appears in the titan's place is photoshopped into the scene.