A very big human, carrying around a big rock.
I think it fits perfect to Behemoth
An idea, when he stuns he slams the rock in the ground, causing the the ground in a line to either fall uopon itself or raise, like the old behemoth. Other animations should be with the rock slaming, just like old behemoth.
Have fun.
Check him out at link. http://www.frithjof.de/asterix_obelix3.gif