Khan’s intuition told him the snake was going to hurt Charlotte if he didn’t intervene. Immediately, Khan leaped into action and saved Charlotte–even though it cost him his life. After Khan got bitten by the snake, he continued dragging Charlotte as far away from it as possible.
Catherine and her family thought Kahn was attacking Charlotte when really he was trying to protect her. Despite all odds, Khan attached himself to his new family so much that he would risk everything for them.