Examine the Rubber Coin

It's a black coin about the size of your palm, made from the sort of stiff but pliable rubber they make tires out of. It doesn't seem particularly edible.

On one side, there's a portrait of some kind of hideous beast. It's all hungry eyes and slavering teeth. Definitely not the sort of thing you want to run into in a dark alley.

The other side of the coin is blank except for some small text in the middle, reading "Don't look behind you."