Bali tigers are extinct now, but they used to hunt pyhtons so sorry 'UNnaturally blonde' but your argument is useless. Balinese tigers are the smallest of the nine sub-species, imagine what a Siberian or Bengal tiger would do.
It really depends on their sizes. A small snake would easily be killed by a tiger. I large constrictor, such as a rock python, could overcome the strength of a tiger. A large snake is actually much more stronger than the average tiger. On the other hand, a venomous snake would most certainly kill a tiger too. If it were to get a successful venomous bite, then the tiger would eventually die from the effects of the toxins. Like I said, it just depends.
Ofcourse a snake. Once, the snake lock tiger's neck, it won't leave him before his death.