The Four Symbols are ancient celestial beasts whom have existed through-out history. During the period between Izanagi's death and rebirth, they remained in their dormant forms as star constellations within the night sky.
The range of abilities what each beast perform differs between them. Their physical form and aligned element determine this. But each are able to shift into a smaller shape and size called their Mitama (神霊; Literally meaning "honorable spirit") forms. In this compact form, they are able to attach themselves to a person and gather natural energy for them.
Kohryu is the celestial beast who reigns over the Four Symbols, and represents the center. He appears as a gold, long, scaled, serpentine creature with four legs of colossal size, being one hundred feet in length alone. As the center, he represents the earth, and the elemental affinity of it as well. With a swing of his tail, he is able to cause fissures and the rising of the earth. His scales also provide great defense, being even greater than Genbu's shell. Though, he is lazy to take action, and prefers to take it whenever it is in his favor or self-preservation. This usually requires one to mount him.