I mean the best look we get is at the very end of Dragonstorm, where Jormag gets its front limbs fully in the picture, and it looks kinda weird - it's hovering there with claws ready to grasp like a human would when preparing to grapple with somebody, but remember that the rest of Jormag's body is located horizontally, farther in the back, not below it. I'd say it either has to be very long and serpentine to make such pose possible, or has more than four limbs to support itself.