Ever since its 2013 premiere, Attack on Titan has wowed audiences with its grim, dystopian world in which Titans threaten to devour the entire human population. For many years, fans wondered why the Titans, who don't possess digestive organs, need to eat humans. After all, the giant humanoids get all of their energy from sunlight, and even more mysteriously, they never attack animals. Humans seem to be the only living things Titans go out of their way to attack.

The reason for the curious -- and gruesome -- behavior was finally revealed in Attack on Titan Season 3, although hints were sprinkled in the second season. And the truth is not just horrifying, but also surprisingly tragic: Titans eat humans because they subconsciously hope that one of their victims will possess the power of the Titan shifters, which would then allow them to transform back into humans.

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The first clue was shown when Ymir revealed her true identity. According to Ymir, she was a wandering, mindless Titan for decades until she ate Marcel, a Titan shifter and companion of Reiner, Annie and Bertoldt. After eating Marcel -- led by pure instinct alone -- she regained her human form. Ymir described her memories as a Titan as a "long nightmare." Ever since that revelation, fans have theorized that Titans search for humans following a subconscious wish to regain their human form and, thus, wake from their painful, dream-like state.

With this new information, Titans become sympathetic and tragic, completely unlike the evil impression they gave in Attack on Titan's first season, when fans weren't aware that Titans used to be normal humans. This theory was fully confirmed in the first part of Season 3, when Rod Reiss transformed into the largest Ttitan seen in the anime to that point. The episode after Rod's transformation also gave fans a glimpse into how Titans viewed humans, as the camera took on Rod's perspective, and revealed a vision that only saw concentrations of glowing dots in the distance. The enormous turkey-like Titan obsessively moved toward the source of enticing light, like a moth to a flame, unconscious and unaware that those lights were actually humans.

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That reveal also explains why Titans are attracted to large, populated cities instead of individuals, and why Titans don't fully eat a human, and instead only consume the portion that contains their spinal fluid. Once a brainless Titan finally finds and eats the spinal fluid of a Titan shifter, that Titan (as seen when Armin ate Bertoldt) will transform back into a human and regain his/her consciousness. However, it also becomes the inheritor of that shifter's power, as seen in the Reiss family's practice of passing down the Founding Titan's power through cannibalism.

Although Season 3 revealed a lot, it did not reveal everything. Questions still arise as to why humans appear as a glowing light to Titans. Some have theorized it's because of the paths that invisibly connect all Eldians (the only race capable of becoming Titans). But that theory has its own problems, as it does not explain why Titans also eat non-Eldians, such as the Marleyan Sergeant Major Gross, as seen in the second part of Season 3.

It could be that non-Eldians are also connected by paths, but that is unlikely considering they cannot transform into Titans as Eldians can. Whatever the answer may be, it may finally come to light in the fourth and final season of Attack on Titan, currently planned to be aired in the Fall of 2020.

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