If you think about it, the world of the popular anime Attack on Titan, where people live behind giant walls, would fit into Civilization V really well. So it was only a matter of time that someone added Eren Jaeger of The Walls as a civilisation for the game.
Steam Workshop user Yuuko, who created this Attack on Titan mod for Civ V, added custom buildings, units, and abilities. He also changed the stats on standard defensive buildings to make this civilisation as much like the anime as possible.
As a future improvement, maybe he should put the colossal titans in too. Those would look so cool on the Civilization V map.
Attack On Titan Civ [Yuuko, Steam Workshop]