I would love to see a plugin that can modify the frequency at which various mobs spawn. What I mean by this is something that would allow certain mobs to spawn more or less often than normal, or not at all/ This would be useful in creating a server primarily populated by zombies or creepers for a different kind of gameplay. This may be bordering on a new plugin altogether, but it would also be nice to be able to keep hostile mobs from catching fire during the daytime. I'm not sure how possible or difficult to implement that would be though.
Already a mod called Ignite which prevents them from burning. However, as for spawning mobs, I agree. I made my own little post about it too.
