catapult

What could I use to build a Plagueclaw Catapult? There are 3 crew right? Any other helpful comments appreciated.

I figured I'd throw up some picture of my ongoing TK projects for all to see. Might give some people some inspiration (including me to stop watching tv and get back painting) My name sake... MC Bone Giant Scatapult with flaming skulls Tomb Scorpion cleaving an Empire Man at Arms apart...