Mystery Coin

I realize this mystery probably won't be solved without a picture posted, but currently I am unable to do so.

The coin was given to me by a teller I know. It appears to be made of brass or copper, and is about the size of a nickel.

There is no lettering whatsoever. On one side is a coiled snake, wearing a crown. Protruding from its mouth is what appears to be a trident. On the other side is a square, and within the square is a series of lines.

Now, I'm sure some will say this is just a token, but something tells me it is a coin.

If anybody can identify this piece of numismatic mystery, I would be most grateful. If not, we'll just have to wait until I learn to post pictures.

Thanks.