I possibly would fear genuine non-human intelligence (on a principle of fearing what we don't understand), but given that chances of one evolving under our nose, on its own, entirely within its own world, without the connection for ours, then emerging, are quite improbable... Unless real aliens arrive - but let's avoid spoilers for 2025 this early.
What should I fear, I think, is hostile intelligence, but then I'm not sure I should discriminate on its origin. I mean, there are some very real humans out there who can try to end this world (in one way or another), so I'm probably kind of desensitized and isn't exactly afraid of some very theoretical AGI threats.