Not Leviathan, so what is it?

[Daku_Naito]

Well the pink one could be a sub-servant of Leviathan or perhaps a pet of the Shangins (Much like the Almaja have Drakes or the Xali have Dogs) which would make sense.

Though on a note when your doing the Mini-Ifrit quest in Limsa, the GC Quest NPC does mention that Limsa had successfully defeated Leviathan on it's own making me wonder if they defeated the Pink one instead of the Primal itself.

It would make more sense if they defeated the blue one instead of the "real" pink one. As they actually showed them fighting the blue one. And the pink one seems to have far more detail, and is far bigger.