Lesser Kaiju?

[Efrate]

I am currently running A PF game in a homebrew setting, and Kaiju are kind of a key element. Problem is PCs are level 9 and Kaiju start at like CR 20+.

I know there is some kind of giant Moth in I think inner sea bestiary, and I can reflavor a few magical beasts I am sure, but barring applying the young template a bunch of times nothing else is sticking out to me.

Ideas or options of kaiju like critters in the CR 9 to like 15 range? Please and thanks.

[Biggus]

That's pretty much dinosaurs isn't it? Give them breath weapons or some other kind of energy attack and you should be good to go.

Other than that, looking at the list of PF kaiju, and lists of monsters Godzilla has fought, there's a giant scorpion, eagle, octopus, praying mantis, a sea dragon/serpent, marine reptile, and crab/lobster thing. Some of them have extra heads and/or tails as well as energy attacks.

For the ones which don't resemble real creatures, there are some aberrations (aboleth, delver, destrachan, otyugh, chuul) which wouldn't look out of place, although some might need advancing a few HD. Maybe even throw in an odd ooze or plant for variety, Godzilla fought some pretty weird stuff.

[Jack_Simth]

There is also the Giant Template (https://www.d20pfsrd.com/bestiary/monster-listings/templates/simple-template-giant-cr-1/) for the purpose. Add that a few times, some extra hd, a thematic special attack, and you are good to go.

Edit:
Also note that you might not want your beasts to be level appropriate. Part and parcel of the genre is that they wipe the floor vs. basically anything short of another of their kind.

[Efrate]

Thats a nice play to start thanks. I expect to build up to the big ones, they are fighting the youngones, so things like rocs thats are like half x for a breath weapon or something work.

[smetzger]

Most (maybe all) Dire animals can be advanced to Huge.
Owlbear advanced to Huge
Gray Render advanced to Huge
Hydra
Howler advanced to Huge
Kraken

You can then throw a template on them.