Simple, Your mind is manifesting a symbol which is alerting you of immediate danger, seeing how a Diamond shape marking on the snakes back is a sign representing a diamond back rattler snake which is very poisonous. Try to understand that something in your dream represented personal danger and your attempt to run, only to have it chase and try to bite you, symbolizes both fear and the need to flee. The question you need to ask is, what were you doing at the time the snake appeared in your dream? I hope this helped.
Leerick
You should check drawing by Dhali: "Dream Caused by the Flight of a Bumblebee around a Pomegranate a Second Before Awakening"
it means you have lunatic dreams, are in a mental state, and should see a doctor.
if it has a rattle then its a diamond back rattle snake. i don't know where you are but those are found in Arizona and other states near by. diamond back rattle snakes are extremely venomous and you should stay away from them.
The snake with a distinctive white line running down its back is called a California kingsnake.
Black Snake Diamond Röle was created in 1981.
This dream suggests the dream is given the opportunity to choose piety, right-thinking and prosperity. Because the snake is looking at the dreamer, the emphasis seems to be on the dreamer's choice between knowledge (with righteousness) and ignorance (with sinfulness.) See the attached link for further information.
By shooting at it
A snake in dream represents a person who lives in a valley. A snake in a dream also means enmity from one’s in-laws or children, or it could represent the evil and jealousy of one’s neighbor. A sleeping snake in a dream means a sleeping enemy. As for an unjust person, a water snake in a dream means receiving help, or it could represent a verdict. Owning a snake in a dream means gaining power and authority. Its flesh represents enemy money, or it could mean joy. If one sees himself wearing the skin of a snake in a dream, it means that he will unmask his enmity toward others. Killing a snake in a dream and staining one’s hands with its blood means destroying one’s enemy. A snake in one’s dream also represents a rich enemy, for its poison means money. If one sees snakes being killed in the streets in a dream, it means a war. source: islamicdreamguide . com
snakes cannot run because they don't have legs, however if a snake feels threatened it might chase a person away from its area.
smash it with a rock
Nothing
The snake is representing someone that you know in the real world.