You should read into more folklore & mythology about animals, I think.
Snakes represent rebirth, healing, & protection. (Forgive me, I have't studied this specific part of art history in two years so I'm a bit rusty) If you were to check out certain Buddhist sculptures in Cambodia during the Angkorean period (like at the Angkor Wat or Angkor Thom), you'll see a common imagery of Buddha in meditation while guarded by a serpent. This is Mucalinda, the King of Serpents, a being who protected Buddha from a storm while he was in deep meditation while seeking enlightenment. He is considered a connection of humans to nature.
In Hinduism, snakes can be both forces of good and evil, but they are generally only evil to those who mistreat the environment. They are commonly associated with water and guardians to the rivers, lakes, seas, oceans, streams, wells, etc.
In Greek mythology, Asclepius was the god of medicine. He wielded a staff with a snake wrapped around it, and many scholars believe it represented how a dangerous creature could become one of healing. This is similar to a few Biblical quotes about Moses and his staff which is shaped like a snake.
Numbers 21:5-9 said:
5 they spoke against God and against Moses, and said, “Why have you brought us up out of Egypt to die in the wilderness? There is no bread! There is no water! And we detest this miserable food!”
6 Then the Lord sent venomous snakes among them; they bit the people and many Israelites died. 7 The people came to Moses and said, “We sinned when we spoke against the Lord and against you. Pray that the Lord will take the snakes away from us.” So Moses prayed for the people.
8 The Lord said to Moses, “Make a snake and put it up on a pole; anyone who is bitten can look at it and live.” 9 So Moses made a bronze snake and put it up on a pole. Then when anyone was bitten by a snake and looked at the bronze snake, they lived.
Also, outside of the realm of myth, the poison from snakes can be used to create medicines.