Also, I loved the backstory of Cubone's skull but I'd love to see a pre evo before the skull because it's kind of confusing to know it hatches with the skull of their dead mother's on them. I don't know, I doubt present Pokemon even hints of Pokemon death anymore but I think that should be corrected or atleast approached.
People have already mentioned Lapras but I would love a pre evolved form of that Pokemon because I've always loved Lapras.
EDIT: I just read Yusshin's post and I was like "yes to all that!". Farfetch'd could definitely use some attention and I would love to see an evolution for that.
What about Girafarig though? I think it could definitely do with an evolved form.
Maybe it's more gore-ish than you think.
I think some Pokemon should remain evolution-less. It gives them a type of charm. Girafarig may be one of them. What could a giraffe possibly turn into anyway? I can't think of anything...