The relationship in the analogy "snake is to his" suggests looking for a word that is related to "saw" in a similar manner.
Interpreting "snake is to his" may lead us to consider the possessive aspect. The phrase could imply ownership or something that belongs to the snake, which sounds like "his."
For "saw," a similar relationship would involve finding something that it does or that is related to what the saw does. The word "cut" is directly connected to a saw, as a saw is a tool used for cutting.
Therefore, the answer is:
cut