The problem with crossbreeds or mongrels is that they take some genes from both parents, but you will never know which ones they will take after, even within a litter there may be several different types. Even the 'designer' crosses such as Labradoodles or Cockerpoos may have very different traits from their brothers and sisters, i.e. some may be curly, some may be smooth, they may be different colours or sizes. Factor in yet another cross in the parents generations and you end up with a melting pot of assorted colours, sizes, coats and of course temperaments. This is why many people prefer a purebred or pedigree breed, so they know within a little what sort of dog they are going to end up with. You are very unlikely to find a replica of your previous dog, even cloned animals do not neccessarily resemble their parents. Also even if they do look like your dog, the temperament may be totally different.