Springtrap

Springtrap is the main and only corporeal antagonist in Five Nights at Freddy's 3. He is the mutilated corpse of William Afton trapped in a massively-damaged rabbit animatronic suit. He returns as a digitally re-created version of Afton on charmer's channel.

Appearance
Springtrap is an early model of a Bonnie suit, as he is referred to as Spring Bonnie by Phone Guy on Night 5 and by the girl in the Night 3 minigame of Five Nights at Freddy's 4.

He is a heavily damaged rabbit animatronic/springlock suit of a drab olive color, with darker colors on his stomach and insides of his ears. A great portion of his right ear is missing, with wires sticking out of the stump left behind. Springtrap's entire body is torn and tattered with gaping holes exposing caging and wires throughout, thus making Springtrap appear much more macabre-looking than any of the other animatronics from any previous installments in the series. His brown/green nose has an irregular squarish shape due to deterioration. While both hands and feet are attached and generally intact, his legs are entirely stripped from the mid-shin down, fully exposing endoskeleton metal and wiring. Several finger joints from each hand are missing their suit overlays. The middle and pinky fingers of his right hand are notably missing their fingertips. A single black button can be seen on the middle of his chest. If one looks closely at the large hole from his chest which is located under his button, there are multiple red lines.

His endoskeleton feet appear wedge-shaped with each sporting five toes. As of 8/8/16, pictures of an early Springtrap model show his visible endoskeleton torso in a shape of an upside-down triangle. It has six "ribs" that almost act like real ones. It also has several "blood-veins" drooping on each side.

Both of Springtrap's eyes are properly set inside his head and appear to be pale gray in color. Oddly enough, the eyes themselves are larger, matching to those from an animatronic than a human, as the corpse contained inside Springtrap is that of an animatronic endoskeleton (with the mummified skull, innards, and blood-veins his only remains). However, the eyes are also deteriorated and printed with nearly visible blood vessels, causing them to look rather eerily human-like. Each iris is black and grayish-green in color with glowing white pupils.

Springtrap has a permanent, wide grin as the material surrounding his teeth has deteriorated. In a paranormal-like matter, his jaw can be seen moving (while the mouth from his trapped, soulless body cannot move) in occasions, such as during his second jumpscare, on CAM 15, his first rare boot, Scott Cawthon's "Thank You!" image, etc.

Close examination of Springtrap and the rare boot images depicting him show that there appears to be human remains within the suit. When viewing the torso and other exposed sections of the endoskeleton, there are chunks of dark pink material that resemble human innards. His neck is covered with lines resembling blood vessels. In the boot images, Springtrap has his jaw open and is pulling the suit's head up, revealing a mummified-looking human head. It is reddish-pink in color with its eye-sockets larger than the eyeballs. Its mouth always remained open with crooked teeth and what appears to be few long strings. The jaw and teeth of the head can be briefly seen during his second jumpscare, and can also be seen when he's on CAM 15. The corpse's head can also be seen clearly from Springtrap's early model screenshot. It is revealed in the end-of-night minigames (after completing Night 5) that these are the remains of William Afton after he was killed by the springlocks within the suit. Strangely enough, from Springtrap's render modelling screenshot, William's corpse doesn't have any ears at all, though the ears may have rotted away over the years