As a human, he resembles a rather dwarfish man with an extremely torn outfit resembling a bag for potatoes almost. He's bald, with a few hairs sticking out of the top of his head and his eyes lack pupils. His teeth are also prominently sharp in appearance. As an Apostle, he grows to a much larger size (though about Average for an Apostle, not huge) and forms a second head ontop of his original body. In this form his human form is mostly morphed into the larger body, with just the small deformed arms and face remaining just below the chin of the new head. The larger, Pig head has large tusks poking out of either side of its mouth, while it's cheeks sag down much like a bulldogs. The rest of its body is pretty bulbous in appearance, with chubby arms and chubby legs.
He tracks down Guts to Godo's place, by following his scent over a long distance. Guts breaks his new sword trying to wound the tough creature, and the fight would have gone badly for him if he had not discovered the two weapons which were to become his trademarks: the Cannon Arm and the Dragonslayer. By using these two new weapons, Guts manages to kill the Swine Apostle rather easily.