. >> reporter: danielle tarantova told my "nightline" co-anchor dan harris that cloning her dog trouble was worth every penny. >> i couldn't believe it. it's amazing. everything is the same. everything. even his personality is the same. what trouble used to doe does. >> so his name's double trouble. >> yeah. first one's trouble. second one's double. they say there are tons of other potential pets out there who are looking for homes. there are some who worry this could be a slippery slope to human cloning. plus for those people forking over major money there's no guarantee your cloned pet will have the same personality as your original pet. >> nature versus nurture. so genetics also plays an important role in it, but also the environment of it. there are very characteristics as well that are very similar to those of the original donor. >> reporter: but laura and richard seem like perfectly happy customers. >> we know it's not dylan. and just to get that piece of dylan, i mean, i'll basically be able to see dylan's face. and just having that part of him like a member of his family just me

. >> reporter: danielle tarantova told my "nightline" co-anchor dan harris that cloning her dog trouble was worth every penny. >> i couldn't believe it. it's amazing. everything is the same. everything. even his personality is the same. what trouble used to doe does. >> so his name's double trouble. >> yeah. first one's trouble. second one's double. >> reporter: but critics have major concerns. they say there are tons of other potential pets out there who are looking for homes. there are some who worry this could be a slippery slope to human cloning. plus for those people forking over major money there's no guarantee your cloned pet will your original pet.