Ethan/DarkStorm from a different timeline, where he is friends with Endo, and was stuffed into a model (not the model, but a model) of Golden Freddy. He is now a spirit in Freddy Fazbear's.
Ethan looks as he always does, black hair, slightly pale skin, and skinny. He is wearing the clothes he died in, a T-shirt and jeans. His entire body is translucent, and is entirely colored pale hues of white and blue.
As a spirit, Ethan can fly and walk through walls, like any ghost. He can also communicate with other ghosts, including the other animatronics' spirits.
As an animatronic, Ethan looks almost exactly like Golden Freddy. The only difference is that he has eyes with red irises and/or white pinpricked endo-eyes.
Ethan has the basic abilities of any animatronic.