Porky is a pig animatronic that replaces Bonnie. He is one of the two animatronics that start in game at night 1, the other being Buzzy. He is the least active animatronic but still moves around quite a bit. There is an easter egg where you see a human arm coming out of his mouth. On night 3 the phone call states, "Uh-you know Porky? Well... I-it turns out he's hostile. I mean... H-he kind of.. Ate them. Ya... I know. He ate someone... S-so ya."
Porky can come from both doors, when he comes through the door he can be seen crouched under the players desk. After 4-20 seconds he will attack the player. He has the ability to quickly turn his head towards the camera and it will fuzz out. It has something to do with an accident while making him where his eyes will flash into screens (cameras) and break them, but since you have very hi-tech cameras, they will only fuzz out for a few seconds.
In his jump scare he will jump out at you then the screen turns to static.