What is this strange place that Geoffrey has stumbled upon?

Even more peculiar is the individual behind the booth.

He has asked Geoffrey to bring him any Gerbil Coins he stumbles upon.

In exchange, he is offering Geoffrey access to his wares. But so many questions come into Geoffrey's mind.

Just who is this odd-looking character sporting a monocle and top hat? Where did he come from? How did he get here? And why is he ... green?

Come to think of it, the inscription on the coin bears a striking resemblance ...