The Wall Titans (壁の巨人 Kabe no Kyojin?) are unusual Titans that make up the Walls that protect humanity. It was first revealed when the Female Titan tried to climb Wall Sina to escape from Eren Jaeger and the Scout Regiment. The lack of sunlight inside the Walls renders them immobile.
The Wall Titans are similar in appearance to the Colossal Titan in that both their surfaces are covered primarily in muscle tissue and lack skin (although the Colossal has exposed bone over the muscle tissue of its form). They have proportionally small eyes and lip-less mouths which exposes their teeth. Their exact height is unknown, but seeing as they make up the Walls, it is implied that they are extremely tall.
It is implied that Wall Titans have the ability to use their crystallizing powers to create massive Walls.
During the battle between Eren Jaeger and Annie Leonhart's Titans in Stohess District, Annie attempts to escape by climbing the Wall but is stopped by Mikasa Ackermann. It damages part of the Wall, however. after the battle, a huge chunk is torn off, revealing the face of a mysterious Titan.
The missing chunk of the Wall is later noticed by some Scouts. The Titan within the Wall follows the Scouts' gaze. Pastor Nick then catches up with Hange Zoë and calls for the immediate covering up of the Titan, as the sunlight eventually will enable its movement. After Nick ignores Hange Zoë's questions about it, he is nearly thrown off the Wall by her, but still refuses to reveal any details he might know because of the Order of the Walls' forbidden nature to disclose secrets.
During the expedition to Shiganshina District, while thinking about where Reiner Braun and Bertholdt Hoover might be hiding, Armin Arlelt remembers the Wall Titan found inside Wall Sina, which makes him deduce that the Warriors may be hiding in a cavity in the Wall, as this provides a high spot from where they can watch the Scouts' movements while staying out of sight. This is proven to be true after Reiner Braun is found hiding this way.
- In the second compilation film, the Wall Titan's design is slightly altered to make it look more like its manga counterpart.
- This change stays in Season 2 of the Attack on Titan anime.