OT for ACtoolkit, but an interesting future feature:
> ...The NPC's names are stored in the save file? Why would they do that?
I suspect that's for downloaded content.
In the old AC:WW, there was a single byte for the species. That one byte gave you the name (eg: "Opal"), the default catchphrase (eg: "gronk"), the 3D model and texture/coloring. You could customize the one catchphrase. Very limited.

In AC:CF many things are separate. There are 7 (or 8?) different languages for the name and catchphrase. You can change them all. There are other attributes not yet explored. It also includes the texture map for the 3D model (it looks like the 3D models are fixed, but the coloring is flexible). Ie. you can create new kinds of Elephants, Frogs etc.

See this photo for a mutant Opal (Opal is normally green): http://www.aibohack.com/wii/teaser4.jpg