He might be a lethal animal, but has a good heart and only strikes when he's being attacked. His name is Steve, a shy snake that speaks, is afraid of loud noises and gets sad when offended. Black mambas are shy but aggressive, and if cornered, the snake may rear up and threaten with an open mouth and a slightly expanded or flattened neck (or hood) before striking. Black mambas can strike repeatedly, injecting its deadly neurotoxic venom which causes difficulty in breathing within half an hour.