This is currently my pride and joy, the Ultraforge dragon. In my opinion one of the best dragon models out there. As you may notice it's far from finished at the moment, the paintjob needs some cleaning up, it'll get a rider for it, and it needs a base.
This model is my counts-as Thunderfire Cannon. It's based on the old metal Lizardmen Stegadon model, with the horns replaced by brain-implants. The turret consists of a regular, round 25mm base (with those weird hooks from the vehicle accessory sprue stuck on the side) topped with a Rhino driver's hatch. The gun itself is a cut-down twin-linked lascannon with the covering plate of the Vindicator's robot-arm (the one that holds the shell) stuck on top.