Someone else correct me if I'm wrong but including anything in the server that's not an actual part of either the game, expansion, or mod download requires the person connecting to install that themselves on their local install.
There are a couple of notable exceptions in that you can make some minor changes to a few textures and add in some sounds but these are clumsy and not easily done as they are in other engines. I don't think I've read any way at all to bring in a model package though and certainly not the animations that would go with it.