Hmmm. If it’s supposed to be classic zombies only, I don’t see why there would be any traces of giant spiders. The webs and eggs must be spawned independently from the giant spider monster, so they’re being overlooked by a game mode that only removes monsters.
I hope someone can verify that, I doubt it would be much of an issue to clean up the classic zombie mode to not contain artifacts of default gameplay like that! I know what it’s like being freaked out by things in a disproportionate manner, and it sucks. I think it’s a logical edit to be made anyway, and it suits your needs, so win-win.
Now if only I could code. (this post was mostly so I could follow how the suggestion is handled - my notify button does not, in fact, notify me of anything in threads.)