I've noticed Poodle mixes such as Cockapoos, ShihPoos, Pomapoos
etc tend to almost look exactly like they did as puppies. Teacup
and Tiny Toy Poodles with the baby doll face look like puppies as
adults. American Cocker Spaniels still look like puppies as adults
sometimes, some Yorki mixes like Morkies also look like puppies as
adults. I think fluffy or curly dogs with a shorter nose tend to
look more like a puppy as an adult.