Pighead is the main antagonist of Saw: The Video Game. Pighead is a masked and silent character, never speaking a word in the game. Pighead is apparently an apprentice of Jigsaw, the villain of the Saw franchise, he has had two other apprentices in the series: Amanda Young and Mark Hoffman, but neither one is the character.
Pighead kidnaps the games hero, David Tapp and has a key put in his chest before placing him in one of Jigsaw's reverse bear traps, after the man is shot by Zep Hindell (another one of the saw victims) and left injured in the sewers near Jigsaw's lair in the first saw movie, where Jigsaw apparently discovered him. After Tapp escapes the trap he learns that Jigsaw had taken him to an abandoned asylum where he has several other victims locked away in, it is also discovered that the key that was put in his chest can be used to open the various traps in which the other victims are encased, hence the other victims are given weapons to kill Tapp with so they can free themselves with the key they plan to cut out of his chest.
Pighead appears throughout the game to kidnap you and force you into traps, he also appears once to fake the kidnapping of Amanda, who has joined the game to help test Tapp, so as to get her out of the asylum without Tapp learning she's an apprentice of Jigsaw now that his part has been played. At the end of the game Pighead becomes the only boss, Jigsaw informs Tapp that Pighead is disobeying his orders, planning on killing Tapp even though he had finished his tests so he can surpass Jigsaw, Pighead arrives and tries to kill Tap, but Tapp eventually electrocutes him to death, an act that Jigsaw calls murder.
Pighead's identity is never revealed in the game, as he never speaks and his face is never seen, even after he is killed, Tapp does not bother to remove his pig mask. This person is likely a never before seen third apprentice of Jigsaw, it is unlikely that we will ever learn who he was. It is confirmed that Pighead is male however, because whenever he tried to strangle Tapp he would kick him in the groin and run away.
Another Pighead appears in Saw II: Flesh & Blood. Unlike the original Pighead, Pighead II (as the character is called) lives, and like the first Pighead his identity is never revealed. At the end of the game, in one of the various alternate endings, the game's hero Michael Tapp (son of David Tapp) is given an option to wear a Pighead costume and serve Jigsaw alongside Pighead II, his choice is never revealed. The Pighead from the first game is also mentioned and it is revealed that Tapp felt guilty of killing him since he may have had a family and been forced into working for Jigsaw.
Pighead wears a red robe and pig mask, which is where he gets his name. Pighead II looks exactly the same. Both Pigheads 1 and II are very brutal, intimidating, and sadistic, happily killing victims even when Jigsaw tells them not to, which also shows that neither of them are very loyal.