Selectively breeding humans for intelligence is frowned upon, but nobody seems to care about selective breeding for non-human animals. Sheep get fluffier, cattle get beefier, dogs get doggier. You’re a mad scientist who’s managed to put together a decently sized operation with lots of loyal underlings who will carry on your work for generations to come. Your goal – in the shortest amount of time possible, use selective breeding (no direct DNA modifications) to create a non-human animal species with the ability to verbally convey its self-awareness to you.
Why not crows? I’ve heard that they are actually pretty darn smart to begin with. It would be fascinating to see what would happen if we boosted them up to human-level intelligence.
Which animal? All of them! If it works, I’d do my best to make one of Linebarger’s visions come about. Of course, I’d be one of the Lords of the Instrumentality.
Corvids (crow family – previously mentioned… I’d choose the Common Raven, or maybe magpies 'cause they look so cool)
Bears. This has the potential to end up most-likely-to-go-badly, I think.
Great apes. This one has had movies made about it!
Insect colonies (ants, probably) – unconventional choice. Also, I’m not sure how selective breeding might work for animals that breed in colonies.
Rats. Very short generations.
Dogs – they already understand a lot about human communication.
Squirrels.
I’ve often thought of them as natures next monkey.
There would be millions of my pretties in the trees listening in through open windows, watching everyone’s movements and silently committing acts of espionage. I’d rule the world in no time and they work for peanuts.
Remember, you did say “mad” scientist.
Cats. They are probably more intelligent than us now but the question becomes, given the ability of speech, would they lower their dignity to actually talk to us?
Crows/ravens or some sort of parrot. They can already utilize human speech to some degree and are already pretty damn smart compared to the rest of the animal kingdom.
I’m going with an octopus. They’re pretty darn smart already and it would be interesting to have an invertebrate intelligence in the world. (Just imagine the political correctness issues! No more telling people to get a spine, stop being thick-skulled, etc.)
I’m sure intelligent octopedes will come up with insults regarding the lack of flexibility in vertebrates and our insufficient number of manipulative limbs.
If you were of human intelligence, I think that you would want the ability to make and tinker with things. Not having limbs that allowed that would be annoying.
Making a smart ape isn’t very novel, so I’d probably go for octoplurals.* They’re already pretty intelligent and it would expand the range of intelligent life on the planet. They would be able to explore the ocean, build and farm things on the ocean floor, and we’d be able to set up mutually beneficial trade with them.
Insert “octopi”, “octopodes”, or “octopuses” as you prefer.