The Rusty Dots Furby is from Series 8. This Furby is red with yellow spots, and yellow on the tummy. Series 8 was only released in Mexico and some parts of South America, making this Furby very hard to find. It is an old generation Furby (as you can see from the title).
Below are a couple of videos of Rusty Dots Furbys, provided by YouTube user greatbz.