You knew what i was when you picked me up

What this means is that, the Indian knew what he was picking up. He should've never had trusted that snake he knew how deadly they were. You should never trust a snake even if it talks to you. All the snake was looking for was blood and food. The snake wanted the Indian to carry him down just so it could bite him even if he had promised not to bite him. If the Indian knew how the snakes was, why trust it? The Indian just threw himself on the floor and the snake just left him. The snake got what it wanted and just left the Indian to die in the mountains. When you see or hear a snake crying for help don't help it because it will not end up good for you. You should let a promise just fool you especially when it comes from a deadly animal or a horrible person that is just trying to hurt you.