Right now, my brain is mush. You guys told two people that there're aren't any Rouge or Knuckles chao, but I heard on a chao site that a Rouge chao is a dark/running/fly and a Knux chao is a neutral/power/fly. Are these really true? Sorry for the long question.
There is no official Rouge chao. There is an official Knuckles chao, but it's only availble at special events in Japan. Some people make up "chao recipes" to make chao that vaguely look like other characters, but the two you mentioned aren't actual character chao at all; Dark/Running/Flying looks nothing like Rouge, save for the fact that like all dark chao it has bat-like wings, and Neutral/Power/Flying has no resemblance to Knuckles; it just happens to be red.

~ Crazy C Lea