Couldn't get it to work? Try the following:

@prop cat.angry_msg "hisses and scratches at"
=> Property added with value "hisses and scratches at"

And change the line from:
player.location:announce_all(this:titlec(), " hisses and scratches at ", player:title(), ".");

To:
player.location:announce_all(this:titlec(), " ", this.angry_msg, " ", player:title(), ".");

Voila, it uses your property now.

Back to the properties page