Here is Warlord Games' latest Early Imperial Roman model, the Onager - so called because it had a kick like a mule. It's a nice little model, which is easy to assemble and paint, and looks very effective. I think my only criticism is that it only comes with three crew - I added the optio, and could really do with a fifth, casually-posed, figure (for which I have left a space on the base). A figure like the cloaked legionary in Wargames Foundry's 'Emperor Trajan' set, or the guy mopping his brow in the 'Centurion and Legionaries Fortifying Camp' set (link here) would work nicely - but I'm not prepared to pay £18.75 (including postage) just to get my paws on one figure!