Zangoose is a "cat" Pokemon because the translators are morons. The Japanese word for mongoose is "nekoitachi," or literally "cat ferret." Hence, the translators can't translate their way out of a paper bag, and call it that instead of a mongoose.
If you wanna do some mental reaching, Zangoose looks like Ziggy Stardust. And as we all know Ziggy was in a lot of ways like some cat from Japan.
The Tales of series needs more love in America. Won't change sig until Namco gets wise. Started: 9/8/06