I'm curious why you didn't follow the design from WoW? Seemed relatively unique/interesting... As for now, not a bad job, but seems sorta... I dunno, generic? Like a regular wagon-thing, with a crazy heavy stone skull welded to the front, a catapult arm, and then big skull-shield wheels.
Maybe the word is "eclectic". One thing that made the Blizzard's siege engines so cool was that they usually had a solid theme they were built around.
Good start, though; definitely better than what
I could do, so kudos there.
//EDIT// Did some quick Google Image research and realized I wasn't entirely correct; many of those things (the fences on the side esp.) are there).
However, I
still maintain it could use some cohesiveness of design, and at least some "scrunching". It appears the Forsaken Catapult was meant as sort of a "specialty/light-Catapult"; faster, less range, DoT effect (plague barrels), quicker turning speed, etc. Right now, yours more resembles a long-ish wagon-thing. Shorten the base/sides, rotate & re-seat the skull on the front (maybe mesh edit it a bit to look a bit more menacing, like the WoW one)... Then consider re-working the wheels entirely ('round' might be a good place to start
). One big set of wheels isn't a bad idea.
(Again, I don't necessarily argue for
directly copy WoW; however, there are lots of solid design elements that WoW models (Blizzard in general) exhibit, and it would be silly not to learn from some of it.)
Again, good start.