User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-5020152-20121001195238/@comment-5043481-20121002184425

Maybe the projectiles are sand mixed with mucus that dries to form a hard boulder.

As for launching it, I think it is unlikly that it uses peristalsis, as it is way too slow. It takes a few seconds for it to move food with gravity down your throat. I think it is more likely that it has a bellow like structure inside its body that puffs air out of the hole, ramming any obstructions out and shooting them.

What I don't get is why it has no barrel. If you double the barrel length you quadruple the muzzle velocity. With a barrel it would shoot things much better, with more power and accuracy.