One warm spring day when the river ran high, Cobra spotted Water Buffalo downstream.
Cobra slid over to Buffalo and asked; "Would you please carry me across the river?"
Buffalo said "NO! YOU ARE A SNAKE! YOU WILL BITE ME AND I WILL DIE!"
Snake replied "I swear by all that is holy to me that I will not bite you".
Buffalo, convinced by snake's oath, let him slither onto his back and they started off across the river. When they were within reach of the opposite shore, Cobra fiercely bit Buffalo.
Buffalo cried out as he slowly slid beneath the waters "Why did you do that? You swore an oath not to bite me!"
Cobra replied "I'm a snake, it is my nature"