Yes, it's a bit complicated. The clams and corals are like a half-way between an animal and a decoration.

They grow like an animal but they occupy the floor like a decoration. To compound things, some of them have rocks which don't scale while the rest does e.g. fish-eating anemone.

Technically, you can add a "scale" setting to a coral, I think it will probably work OK, but for simplicity I had my artist draw them at full size in game world scale, and then I use the "scaleTheseMeshes" and "scaleTransform" fields to tell the game how to make them scale down to their child size.

Hope that makes sense! :D

It does make sense, but I'm still confused :D What exactly do these do?
"constantTransform" and "constantEuler"
From what I have found, the "constantTransform" just controls how much should it be buried in the ground (y) and the "constantEuler" is the placement angle of the clam. Or is there something else these constants do?

You've got it! :)

I call them "constant" because they don't change with the size of the animal. As opposed to "linearTransform" which is multiplied by the size and added on to the position e.g. at full size it is is multiplied by 1, at half size it is multiplied by 0.5.

If you design the mesh properly so that the origin of the mesh is where the animal touches the ground/rock then you won't need to use that one. Basically it's a fudge factor in case it isn't in the right place after it is scaled with the animal size.

Welcome to game dev! :D

Haha :D I've sure noticed that the leopard clam is floating when it's in the closed position, haha :D I made extra sure mine sit snug!

Ok, last question! Is there a trick to setting positions for corals on rocks (or plushies in gift shops)? I mean, is figuring out the constants for their placement pure trial and error or can I somehow calculate it?

I'm afraid it's mostly trial and error. I have a slight advantage in that I can run the game in editor mode and actually drag them around until they look good, then copy out the coordinates. But you don't have that option unfortunately. Sorry! :(

Gah, darn it!