Giraffes: not really dangerous. They graze on the tops of trees. I don't know much about it, which leads me to think that "giraffe danger" isn't a thing that gets talked about because it's not much of a thing.

Ostrich: They're not bright - the bird's eyeball is bigger than its brain. Last ostriches that I saw were a whole herd that came up to the fence with open mouths in anticipation of snacks, which was kinda cute. I guess a large male could get aggressive and the kick would be very nasty?

Hipppo: Very dangerous. They may be herbivorous but they're aggressive and territorial. They will flatten you if they're in a bad mood, and they're almost always in a bad mood. A hippo is 2 tons of bastard; and don't bother running, they're faster than you, on land or in water. Best to avoid them entirely.

I'm not joking, google "most dangerous large animal in Africa", read about hippos and how they kill more humans than any other African animal larger than a mosquito.

Giraffes can kick lions hard enough to kill them, or at least injure them enough to prevent lions from returning to effective hunting before starving to death.

In my very limited experience (4 or 5 day safari in Kruger), Giraffes are pretty shy, but you really want to avoid startling them or otherwise putting them in a situation where they feel a need to defend themselves or their young.

Yeah, I just couldn’t come up with something safer than that while also being big.

Elephants are mostly safe, except the male ones occasionally snap and hunt humans. So…