If you haven't yet read Vurt by Jeff Noon I'd advise you do so now, as the following text contains spoilers.
Well well my kittlings. The Game Cat is a character in Jeff Noon's fabulous book Vurt. And what a character. Game Cat publishes a magazine about the many Vurt feathers that float around the "real world". Who is the Game Cat? Well, nobody gets to meet him except for a very small few. Those who know, know that the Cat has a small room behind Sniffing General's desk in the Vurt world. Yes, the Cat is a Vurt being. Of course it was not always so.
Cat was once a human being. A pure like yourself. Unfortunately (or fortunately) the Cat had a run-in with the king dreamsnake in a Takshaka feather. He was left with a massive bite that slowly gave him access to the Vurt world without the use of feathers. Wouldn't we all love that? Game Cat was still in the real world at that point, but an unfortunate (or fortunate; it's all in how you see it) incident involving a Curious Yellow feather and a swap forced him into the Vurt world permanently.
Cat has the best collection of Vurt feathers around, and sometimes you can borrow them if you trade him something in return. Cat also the coolest writing style and his very own catchphrase. And it is:
Be careful. Be very, very careful.