History Foreshadowing / AttackOnTitan

* One lyric from the sixth OP, "My War", contains these lines that allude to Ramzi and Halil's deaths from being crushed by a Colossal Titan, because the latter tried to retrieve the former's dropped money during the Rumbling.

* In Chapter 54, Frieda Reiss reads a picture book to Historia on which she exemplifies the subject (a little girl receiving something from a cloaked figure) as a kind and gentle individual whose actions should be followed; later in Chapter 86, Grisha Yeager attests that he had read a similar book during his research into the subject of the Eldian Empire. The book is about Ymir Fritz (the Original/Progenitor Titan) receiving the Titan power from the Devil in a similar fashion as Frieda's book, though the book is material from the Kingdom of Marley, who hate Ymir Fritz and her people, the Eldians, explaining the biased connotations they give to this event (as the Marleyans argue that the Eldians conducted ethnic cleansing against them, and consider them descendants of the Devil). The fact that the Reiss family has this book in their possession also foreshadows that the First King of the Walls [[spoiler:gave up on fighting the Marleyans because he agreed with their beliefs that his people were the devil and deserved to be punished.]]

* A subtle one is during training, Eren injures his head during 3DMG training. He recovers quickly (in one night!) and can be seen with small amounts of steam leaving his head. It's easily mistaken as a visual indication of his embarrassment and frustration rather than his Titan healing abilities manifesting. Though FridgeLogic makes one wonder how the others [[spoiler: especially Reiner, Bertolt, and Annie]] didn't notice this.

* One lyric from the sixth OP, "My War", contains these lines that allude to [[spoiler:Ramzi and Halil's deaths from being crushed by a Colossal Titan, because the latter tried to retrieve the former's dropped money during the Rumbling]].

* In Chapter 89/Episode 59, when Eren's friends were celebrating as they finally made it to the ocean, Eren notes in despair that their battle is not over and wonders 'if they killed everyone on the other side of the ocean, they would be free or not'. Come [[OmnicidalManiac Chapter 123]]/Episode 87...

* A subtle one is during training, Eren injures his head during 3DMG training. He recovers quickly (in one night!) and can be seen with small amounts of steam leaving his head. It's easily mistaken as a visual indication of his embarrassment and frustration rather than his Titan healing abilities manifesting.

* By far THE biggest one, manga only: The very first chapter shows Eren waking up from a dream in which Mikasa says goodbye to him, while the anime only includes this in the beginning of its second-to-last episode specials (or Episode 88 for episodic version). Skip all the way to the penultimate chapter (138), it's revealed that dream was a peaceful vision of an alternate timeline, shared by both of them, right before Mikasa ends Eren's life in the real world.

* By far THE biggest one, manga only: The very first chapter shows Eren waking up from a dream in which Mikasa says goodbye to him, while the anime only includes this in the beginning of its second-to-last episode. Skip all the way to the penultimate chapter (138), it's revealed that dream was a peaceful vision of an alternate timeline, shared by both of them, right before Mikasa ends Eren's life in the real world.

* In the first chapter, after Carla says to Eren, "Do you know how many people have died because they dared to venture outside the wall?" the next panel is a close-up of Grisha reacting with VisibleSilence. This foreshadows Grisha's backstory, in which his sister Fay was killed because they both ventured outside the walls of their ghetto without permission.

* At a war council after defeating the Mid-East Union, general Calvi snarks if there is any possibility to exists any winged titans. Comes chapter 133 and we see the first flying titan.

* In the first chapter, after Carla says to Eren, "Do you know how many people have died because they dared to venture outside the wall?" the next panel is a close-up of Grisha reacting with VisibleSilence. This foreshadows Grisha's backstory, in which [[spoiler: his sister Fay was killed because they both ventured outside the walls of their ghetto without permission.]]

* In Chapter 54, Frieda Reiss reads a picture book to Historia on which she exemplifies the subject (a little girl receiving something from a cloaked figure) as a kind and gentle individual whose actions should be followed; later in Chapter 86, Grisha Yeager attests that he had read a similar book during his research into the subject of the Eldian Empire. The book is about Ymir Fritz (the Original/Progenitor Titan) receiving the Titan power from the Devil in a similar fashion as Frieda's book, though the book is material from the Kingdom of Marley, who hate Ymir Fritz and her people, the Eldians, explaining the biased connotations they give to this event (as the Marleyans argue that the Eldians conducted ethnic cleansing against them, and consider them descendants of the Devil)

* When the rest of the Survey Corps has to hide in a forest in order to ambush the Titans, Jean vents to Armin about the idiocy of the plan which ends with him saying "I don't want to start a mutiny, at least not yet." Come Chapter 51/Episode 38, the Survey Corps ended up starting a coup d'état against [[AncientConspiracy the government]].

** ''At the very start'' of the story, Grisha is credited for successfully curing an epidemic in Shiganshina. Needless to say, the level of development inside the Walls is roughly medieval-to-late Renaissance level, so it's unlikely that they had modern understanding of disease or modern medicine. Of course Grisha brought that knowledge from outside of the Walls.

** During return to Shiganshina, Armin finds a coffee grinder and three cups with residual 'black liquid' that he can't identify. A coffee grinder also has a cameo during Reiner's flashback to Marcel being eaten.

** English dub only: When Mikasa tells Eren's parents that he wants to join the Scout Regiment and they try to talk him out of it, Grisha says, "It's a nightmare, Eren, the outside, you really have no idea." At first you'd think he's just talking about the Titans, but after the reveal of Grisha's backstory and the reality of the outside world, it comes differently.

* In Chapter 89/Episode 59, when Eren's friends were celebrating as they finally made it to the ocean, Eren notes in despair that their battle is not over and wonders 'if they killed everyone on the other side of the ocean, they would be free or not'. Come [[OmnicidalManiac Chapter 123]]...

* By far THE biggest one, manga only: The very first chapter shows Eren waking up from a dream in which Mikasa says goodbye to him. Skip all the way to the penultimate chapter (138), it's revealed that dream was a peaceful vision of an alternate timeline, shared by both of them, right before Mikasa ends Eren's life in the real world.

** A scene portrays a sum setting or rising over a vast ocean. A bird flies over the ocean, after which four people and / or titans rising from the ocean. This could be a literal interpretation of the end of chapter 137, in which Armin's transformation creates a large explosion while Falco's Jaw Titan flies the Survey Corps to safety. The four people / titans may represent the Eldians turning back to normal, namely Jean, Connie, Gabi, and Karina Braun, whose titan forms were shown and emphasized on in chapter 138.

* When the rest of the Survey Corps has to hide in a forest in order to ambush the Tians, Jean vents to Armin about the idiocy of the plan which ends with him saying "I don't want to start a mutiny, at least not yet." Come Chapter 51/Episode 38, the Survey Corps ended up starting a coup d'état against [[AncientConspiracy the government]].

* When Eren kisses Historia's hand and has a flashback to his father killing the Reiss family, he freezes in place and made a rather... bizarre face. Which was rather strange, considering he had already seen the scene once before when Historia touched him under the Reiss chapel. During his dialogue with Zeke in Liberio, as he is recounting his 'disappointment' with Grisha due to the latter's murder of the Reiss children, he also refers to this particular insident, and not the one before. This was explained thirty chapters later, when we realized that Grisha has actually hesitated before killing the royal family and was persuaded into it by future!Eren via the use of Paths, and that past!Eren saw that moment, as well the future memories of the Rumbling that his father received via Attack titan powers. Basically Eren just realized he himself has to end the war for good by committing genocide, and was appropriately terrified.

* In Chapter 89/Episode 59, when Eren's friends were celebrating as they finally made it to the ocean, Eren notes in despair that their battle is not over and wonders 'if they killed everyone on the other side of the ocean, they would be free or not'. [[KillEmAll Come]] [[OmnicidalManiac Chapter 123]]...