I made a Jack Russell Terrier as a copy of my customer's dog Maggie. I used the method where you crochet the entire dog in the back loops and then crochet the fur in the front loops. It's a long and tedious process, but it creates so much realism that it's worth it. The main dog is made with regular worsted weight yarn and the fur is eyelash yarn by Ice Yarns. Some brushing is still necessary to pull the fur out of the crochet stitches. Most of my critters also get a collar and personalized name tag.