Gerald and Saucix climb down the rope and make their way through the crack. Gerald's armor is scratched; fortunately he doesn't get stuck. The crack quickly widens and leads to what looks like a large natural cavern, which continues further away in the darkness beyond the reach of Gerald's torch.
Suddenly a clattering sound echoes through the cave. Gerald and Saucix look around for its source, and see this crawling across the cavern floor.
It is about two inches long.
Remus: Harry... I'm a werewolf.
Harry: Are you fucking serious?
Remus: Well yes, but I don't see how that applies here.