wow... If I can quote jenjens word... what a stunning design, but why it was titled four heavenly beast while theres 5 animal? tiger, phoenix, dragon, turtle and snake... {:3_52:}
^Retno The Tortoise-Snake is called the Black Warrior, it is one creature born in mythology, here is a little info:
Ancient Chinese mythical animals associated with the four cardinal directions: green/blue dragon (Chn: Qinglong 青龍, Jp: Seiryuu) of the east; white tiger (Chn: Baihu 白虎, Jp: Byakko) of the west; red phoenix (Ch: Zhuque 朱雀, Jp: Suzaku) of the south; and black warrior (Chn: Xuan Wu 玄武, Jp: Genbu) of the north, a tortoise-like chimera with the head and tail of a serpent. The pictorial theme developed around the Warring States to Early Han period in China. Frequently painted on the walls of early Chinese and Korean tombs, the animals served primarily an apotropaic function warding off evil spirits. In Japan notable examples of the shishin are found on the walls of the tomb chamber in the tumulus Takamatsuzuka 高松塚 of the Asuka period, and on the base of the Yakushi Triad, Yakushi Sansonzō 薬師三尊像 at Yakushiji Temple 薬師寺, both in Nara.