Mine's a 100-lb. European-bred black and red German Shepherd named Mulder, friend to all but the bad guys, an overachieving retriever, and lost at age 11 to an aggressive cancer. I was 32 when he died, and felt I'd never have another dog again, if only I could keep that one.
Before I pull out my change jars for deceased-dog cloning technology, though, I remember the untold secret of pet cloning: you're buying a breeding technique, not a replacement animal.
This story of Chance the bull and his clone has stuck with me as a prominent example of the inseparability of nature and nature when it comes to behavior.