The fantasy creature I am imagining (planning a short story or two around) satisfies the following analogy:
Human is to Chimpanzee as "This Thing" is to Badger.
That is, the creature has a clear relationship to badgers, such as similar anatomy and behavioral inclinations. But it has also become much more highly evolved and sentient: i.e. tool use, its own religions/mythologies, sophisticated language both written and oral, a structured society with organized government, etc...
I want this creature to retain a clear affinity for burrowing and living underground, eating tubers and worms found underground, making a living extracting minerals from the ground, artwork that relies on things like roots and clay, and so on. Thus it needs to still have digging claws, although it may use picks and shovels for larger and more difficult digging. At the same time, it needs to be able to hold a paper and pencil, make intricate carvings, use needle and thread, and indeed to swing those same picks and shovels.
How would evolution handle this?
I can accept very broad explanations, I prefer to paint my world with a wide stroke, if not with a broom.