Attack On Titan - Season 1 - Episode 1 - To You, in 2000 Years: The Fall of Shiganshina, Part 1 [English Subbed]

Summary :- One hundred years after the appearance of the Titans, humanity receives a grim reminder of the threat that the Titans pose. Under the belief that they were safe behind the Walls, a Colossal Titan peers over the Walls and breaks the Wall. A young boy and his foster sister do what they can to save their mother, trapped below the debris of their fallen house, but they are forced to flee when a disturbing Titan appears. The boy watches as, before his eyes, the Titan picks her up and eats her.