Ilse Langar (イルゼ・ラングナー,Iruze Rangunā?) was a member of the Survey Corps. She was a participant of the 34th Expedition beyond the Walls and was in charge of the left wing of the second brigade. She wrote very useful information about her final moments in a notebook.
Ilse was noted to have resembled Ymir in appearance. She had short black hair that was parted to the right side, and light-colored eyes with a small patch of freckles below each one. She wore the standard Survey Corps uniform and cape.
She appeared to be quite emotional yet brave. She also appeared to think about others, even when she was in grave danger. During her last moments she regretted not being able to give anything back to her parents. She also thought of herself as a proud member of the Survey Corps and was resolved to do whatever she could.
During the 49th Expedition outside the Walls, Hange Zoë among other members of Levi's squad encounter a Deviant Type Titan that, after chasing Hange, turned the other direction and headed farther into the forest. Hange follows it to a forest clearing where it headbutts a tree and it is soon after killed by Levi after almost eating Oluo. Petra Ral points out a decapitated corpse hidden in a hole in the tree, and they find a hidden notebook that belonged to Ilse Langnar before her death.
Hange reads the notebook. It explains that after Ilse's entire flank was massacred, she fled to a nearby forest, heading north. After profuse running, she inadvertently runs into a Titan and writes in the notebook, believing it to be her end. She remarks that instead of immediately eating her, it hesitates. It then addresses her, saying "Ymir's people" and "Ymir-sama", greeting her with deep respect, and bows.
She is thoroughly confused that the Titan can form speech, and writes in her notebook that she has attempted communication. She first questions it about what the Titans are, and building up blind sadness, fear and rage, she angrily yells why Titans eat humans and what their objective is, calling them useless lumps of meat that ought to disappear from the world. The Titan appears more and more frustrated as it moans and tears at its cheeks, ripping off flesh and spraying blood. Ilse attempts to flee but is caught by the Titan, who is rapidly crushing her skull, and Ilse writes down her last few notes about the experience before being decapitated. The Titan later stores her corpse in the tree. Nothing is known about the Titan's reasoning for its actions, but Ilse's notes prove significantly useful to humanity.