My dream about a green cobra...?

I had a dream that me along with some other people I don't know were walking down a nature trail and there was a huge boulder on the side of the path. When I started to walk by I notice there was like rain drops coming from the top of the boulder. So I stopped everyone and stepped away from the boulder to look on top of it and saw a long green cobra stretched out on top of the boulder and each time someone tried to walk past it, it would spit venom over the top... I remember telling everyone to cover their eyes and hold their head down while walking by and everyone did. No one got hurt in the dream and the cobra wasn't any more aggressive... What could that mean?