This is not a Black Mamba, it is in fact an Olive Grass Snake (Psammophis mossambicus). Head structure and coloration is completely inaccurate. Mambas have coffin shaped heads. Side on, the head is elongated and blunt, it is not short and curved as in this photo. Even under low pixelation, a speckled pattern can be seen behind the eye, another typical feature of the Olive Grass Snake.