"Aquaman" had one helluva lunch Tuesday afternoon hitting up a couple of joints in WeHo. Jason first hit up a sushi spot, which begs the question ... is that considered cannibalism? Anyway, he later hit up Joe's Pizza for a few slices.

Jason really loves him some pizza ... and evidently the crust too. He had some fun with the paps too ... bringing out an employee with him and pimping the joint. Sure, he flipped the bird to photogs, but in a playful way ... and they all ate it up.