The Ecological Succession of Ruins and Tomb Cats

So I somehow missed Life After People when it originally aired.  A documentary series on the History Channel, I managed to see the pilot episode from 2008 today.  You can find the pilot in nine segments on YouTube.

Basically, the pilot explains how ecological succession and chemical reactions would alter man's cities after his disappearance, positing what would happen in stages out to 100,000 years.

For the ecology of dungeons, though, the implications are obvious.  Wood would rot first, and wooden structures would be reduced to their components after about fifty years without upkeep.  Brick and concrete would last longer, but might fall after a century or so.  Stone would last even longer, but salts and erosion would eventually destroy it.

Flooding would fill subway tunnels and absurdly spacious sewers within a couple of days after the collapse of civilization; constant water action would cause the support columns to collapse, collapsing city streets into the subterranean canals within 150 years.

After a millenium, most modern cities would be unrecognizable.  After 10,000 years, it is possible that only the Great Wall of China, the pyramids at Giza, and the granite faces of Mount Rushmore would remain recognizable.

(Obviously, this ignores fantasy worlds and magic, but it's still interesting stuff.)

Anyway.  Apart from fantasy streets collapsed into flooded tunnels, they mentioned something I knew, but had forgotten: tomb cats.

The Coliseum's cats are among the most famous, but cats are known to reside in the upper levels of catacombs and tombs, using them as shelters.  They go out to hunt, and then return to their homes to rest.

But what about fantasy tomb cats?  D&D tombs have all sorts of weird magics and eldritch energies, not to mention self-sustaining ecologies, so it is entirely likely that tomb cat colonies in fantasy settings are wholly different animals.

In such a case, it is possible the cats don't hunt outside the tomb, but instead push further into the tomb to hunt.

There you go, you just got a free one-shot — rather than adventurers roaming a tomb, you're a destruction of tomb cats (or maybe your tomb cats are more civilized and you're a clowder of cats instead?).

Anyway, apart from the obvious ecological implications, what about tomb cat adaptations?  Some are likely to just be feral cats, but others might swarm and still others might be dire cats (so, you know, you can reskin all those rat swarms and dire rats — and don't forget that cat mouths and claws are filthy, so infection is still a danger).  Of course, others might be weirder: negative energy cats, shadowcats, and zombie cats.

You should add some tomb cats to your next dungeon, is all I'm saying.

Addendum: Interested parties who wish to add some tomb cats can find a brief discussion, and some D&D third edition system resource document links, in this post.