Oda-sensei likes to create important characters that are based off real-life people and/or folklore. The three old Admirals are based off characters from tale of Momotaro.
I'm curious to know if there is any in Japanese folklore on the two new Admirals: - Issho (or Isshou) is aka Fujitora (purple tiger) - "Green Bull," which Doflamingo talks about in Chapter 713.
I tried googling but I got nothing except for Metamorphic Force.
Does anyone have a clue or something about what animals (and story) these two new admirals are based off of?