“We can only speculate it may have been used in some kind of ritual,”
Or art.
Or something to walk on when it rains.
Before Classical Greece, at least, the was no "Art" as we understand the concept. What we see today as art was in pre-classical time intended to serve a practical function, as part of a ritual to aid in working a spell. In Egypt, for instance, while there was plenty of what we might call "art", there were no art galleries where one might view paintings and sculptures and so forth, simply to admire their beauty. It was all put to use in temples, shrines, and tombs; where art was used as decoration, as in jewelry, it was likewise intended to perform a function, such as to bring good luck and etc.
Going further back, the cave paintings and petroglyphs were not just pretty pictures, they were magic spells, intended to assure a good hunt or fertility, or some other practical goal. Just as this snake figure was, I am sure