Inserting models of different renders

[RoyalEF]

In the HL2 demos at E3 they said that you could have a model (G-Man) of water or fire. Anybody know of how they meant for that to be done. I'd like to use some of the models as statues, which if I could render a model with stone, would make for a very quick statue. If I could make a man out of rolling fire or rippling water, you'd think static stone should be a breeze.

Also can any entities SCALE a model. I'd like the statues to be larger than man sized. Having Breen statues is fine, but if I could make him twice as big and stone no one would think he was a palyable model.