Rivka and Kujiba (Book 2)

[shameknights]

Hey! I haven't been able to find anyone else asking about this anywhere, so I guess this is as good a time to make my first ever forum post as any. I'm making some kaiju-adjacent content for a design challenge and wanted to do some research on the kaiju content introduced in this AP to help.
I noticed that in Ready? Fight! there's a new monster called the rivka, which has an ability that varies based on which kaiju it's fed on. This ability lists some example kaiju and their associated damage types, all of which are recognizable kaiju in the setting...Except Kujiba (who is associated with negative energy).
Like I said, I haven't been able to find anything about such a creature in Pathfinder or real-world mythology, although I've mostly just googled around and searched the forums, so I may be missing something. I also haven't read any of the actual adventure content in Book 2, since I'd like to avoid significant spoilers (I don't think the kaiju thing in general is much of a spoiler, since it was an advertised part of the AP).
Anyone have any idea who Kujiba is? I'm assuming a cut and/or yet to be introduced kaiju, similar to how the Mwangi Expanse ancestries were for a while, but it's weird that it's only referenced in this one statblock with a name and a damage type.

[Grankless]

I believe Kujiba is the giant zombie whale in the Kaiju gazetteer at the back of that book. I can double check later.

[Curaigh]

I think you mean Jakabu. Jakabu is the "Ethereal Leviathan of the Eastern Sea".

Many of the adventure hooks in the various entries mention a rival kaiju. I am guessing Kujiba is one of these, but they are not mentioned in this book. This could be a possible callback to a PF1 adventure, but now I am curious to know as well :)

[Curaigh]

Book 1 mentions a battle between King Mogaru and Frovith the Void Duke who "unleashed a beam of unlife...".

Jakabu is a ghostly leviathan followed by undead seagulls, so does have that negative energy vibe.

It could be a name change in development, for either of those.

[Kitsune Kune]

As I don't see it showing up in book 3 either. I've decided that this is a previously unlisted Kaiju. With that, I DO like the name. Taking the kanji for the three sounds, and common readings from them, I get "The Wing of Bitter Time". Which, to me at least, combining that with negative energy screams of some flying Kaiju, with a power to rapidly age things/creatures. It could even, in theory, age away all legends of itself. As everything that has it's name written on it rapidly ages and crumbles to dust. Leaving him a mystery kept only in verbal legends... (Could even make it so those who know the tales of him ALSO rapidly age...)

Just my fun thoughts on it.