Hippos are the most dangerous animal on the continent - one of the few that kill for the hell of it. Very scary beasts, especially if you are camped along one if their waterholes. Not to be trifled with - keep well clear!
as for the snakes and crawlies, no big deal. Shake out your shoes before putting them on and don't step blindly over fallen trees or put your hand down holes.
The criminals and rogue police, soldiers are another matter. This continent has more than enough if those. There is a reason Niarobi is known as Ni-robbery.
all this said, the overwhelming percentage of people here are friendly, decent, kind - as they are most places - and the scenery and wildlife are truly spectacular, although the Masai Mara may not be the best place to wear heels!