SCP 096. As long as I don't look at him ever im fine. Can't say the same with Nemesis.
Its intelligence was below a human but enough to set traps, use weapons, and remember the faces of stars members. And this one is a nerfed one, I think there was 2-3 other nemesis in lore that escaped due to their intelligence but got put down.
not really sure how you would kill one either. It got decapitated in original RE3 and still pursued. Regular guns will do diddly shit to it as it has body armor everywhere. The best thing you could do is set a trap and dig a real big hole then burn it.
Another thing is the tyrant is just a host, the parasite is really what you're fighting. Hence why when it got decapitated it didn't care.