Xiuhcoatl

Xiuhcoatl (太陽の蛇) is the ultimate weapon of the Return of the Winged One, appearing in Toaru Kagaku no Railgun SS: Liberal Arts City.

Etymology
Xiuhcoatl (meaning "turquoise serpent" and also carrying the symbolic meaning "fire serpent") is a serpent in Aztec mythology, regarded as the spirit form of Xiuhtecuhtli, the Aztec fire deity, and also an atlatl wielded by Huitzilopochtli.

Appearance
The Xiuhcoatl is over 100m long, resembling a rugby ball forcibly stretched from each end. It has several large and small wings on its back and sides.

Principles
Much like the Mixcoatl, the Xiuhcoatl is constructed from wood, cloth and obsidian.