Gorilla any day. If the Black Mamba kills you, it is not a pleasant death, 7-15 hours. Gorilla will probably beat/bite me to death as fast as possible to minimise any risk to itself. The Mamba will also be much more unpredictable vs the Gorilla. But I wonder how this situation would be if it was over a week and not 24 hours
Not that it's a direct comparison, but have you ever seen the video of the baboon ripping a gazelle to pieces from the back end up without a care in the world that the thing is still entirely alive and aware?
That's the thing, though: baboons are absolutely vicious. You can't take them anywhere without them spoiling your day with absolutely unnecessary levels of brutality.
Gorillas might fiercely protect themselves and their family when threatened, but far from being vicious predators, they're mostly pretty chill herbivores who just want to eat fruit and be left alone.