A dangerous snake
The vet told the Svilicics that there was a Mulga snake living on their property. Mulgas are very venomous and poisonous snakes that live in Australia and are extremely deadly animals.
It quickly became clear to Catherine that Khan didn’t mean to hurt Charlotte–he was trying to save her from danger. He must have seen the snake moving toward her and heroically threw himself in harm’s way so she would be safe.