Four Symbols

The Four Symbols (四象, Sì Xiàng) is a recurring theme in the Final Fantasy series. It refers to the four mythological creatures in the Chinese constellation. These creatures represent the four cardinal directions and the four seasons, and are known as:
 * Azure Dragon (青龍; Qīng Lóng) - represent the direction East and the season Spring
 * Vermilion Bird (朱雀; Zhū Què) - represent the direction South and the season Summer
 * White Tiger (白虎, Bái Hǔ) - represent the direction West and the season Autumn
 * Black Tortoise (玄武, Xuán Wǔ) - represent the direction North and the season Winter

While originating from China, the Four Symbols are also widely known in Korea, Japan and Vietnam. Each region have distinct names for the Symbols; in Japan, the Shijin, as they are collectively known, are called Seiryuu, Suzaku, Byakko and Genbu respectively. The Symbols have permeated into pop culture, and has recurred in the series as follows.

Final Fantasy XI
Four Notorious Monsters are named according to the Japanese Shijin, and each refer to themselves as the "Divine Guardian" of the four cardinal directions. These monsters can be found at the Ru'Aun Gardens in Tu'Lia, but only after summoning them using a particular stone and gem named after their respective Season and Direction.

Final Fantasy XII
The boss monsters Slyt, Phoenix, Fenrir and Pandaemonium each are referred to the Sì Xiàng in their bestiaries. They are found at the Pharos at Ridorana both as boss and a Mark hunted within the Subterra.

Final Fantasy Type-0
The world of Oriens is made up of four nations, each containing a Peristylium, or magic academy, that holds a Crystal named after the Shijin.

Final Fantasy Tactics
An Artefact called the "Four-Deity Plate" is described as "a set of four small brooches, each crafted in the image of an Eastern Deity of direction. The intricate inlay of fine jewels suggests the collection once belonged to nobility."

Final Fantasy Tactics Advance
The Shijin is referred to in the "Shijin Shield", a Mythril shield dedicated to the four shijin gods.

Final Fantasy Tactics A2: Grimoire of the Rift
A mythril shield called "Shield of the Four" is described as "made in honor of the Four Gods" and "bears the symbols of the Four upon its surface".