George Jones
Answered October 20, 2018 · Author has 95 answers and 78.1K answer views
A “snake”, also known as “a snake in a grass” or “snake in long grass” refers to the reptile that cannot be easily seen because of the long grass.
When someone calls you a snake, they imply that you are being sneaky and that you are hiding something. Perhaps not hiding, but you are concealing something, like a snake in long grass.
Snakes (the reptile) are known for being slippery and difficult to handle. When someone is calling you a snake, they are calling you a slippery character. That means that you are well aware of your intentions, and ready to escape/slither away when it suits you, whilst keeping such ideas secret from others. Perhaps you are about to cause some trouble, then sneak out the way hoping not to be detected.