They are, essentially, much more customizable and in-depth villagers. These ones aren't restricted to just villagers though, and can be different models, as well as have different roles (such as Denizens, Sentries, Traders...)

Hello.

Bob here.

I would like to suggest the plugin Citizens (http://dev.bukkit.org/bukkit-plugins/citizens/) which adds the ability to add NPCs through commands.

Citizens uses pre-existing models for the NPCs (such as human, dog, zombie, etc.), and appears to have similar functionality to Noppes' CustomNPCs mod (that is, allowing NPCs to walk around, talk to players, and engage in combat with enemies).

At the moment, the plugin is only compatible with 1.8 in a dev version, so it would be up to the staff as to whether or not they are comfortable with that.

As for how it could be used on the server, it could be used at spawn or warps for more flavour, and perhaps as guards for such zones as well. Also, possibly they could be added to towns as well (with staff supervision, of course). All this however is just some ideas I had, how the staff decide to use NPCs is up to them.

Discuss!