Rex's (the lazy lion) is named Sundae/Sunday (there's no difference in how these are written phonetically in Japanese; "Sandee" would be the exact transcription). I think that name is just so much cuter, and fits his lazy boy personality better. He also says "daon" instead of cool cat. "daon doesn't exactly have a meaning, it's just kind of a sentence ending that adds flavor, and i think meant to sound like lion, but it is much better than "cool cat". I find I like him much better in Japanese than in English (I am a native English speaker but play primarily in Japanese in which I am reasonably fluent, for context).
I agree that Chachamaru is a great name!
I also like Fauna and Flurry's names in Japanese more. Fauna is Doremi (Do-Re-Me, get it?) and Flurry's is "Yukimi" (a girl's name meaning snow). I just think they are prettier names.
Lastly, though I don't have either of them, in Japanese it is the smug anteater who wears the mariachi clothing who is named Antonio, and this just makes so much more sense than "olaf" I don't understand this change, to the point where i wonder if it was a mistake in some point of the translation that they just stuck with.
I could go on and on, and might later...