The wiki says that Shadow Freddy appears in The Twisted Ones Novel

FNAF Easter Eggs to Find - FNAF Insider

Freddy Fazbear (FNAF Books), Villains Wiki

Shadow Freddy, Villains Wiki

Five Nights at Freddy's Character Encyclopedia

Five Nights at Freddy's: The Twisted Ones (Graphic Novel)

What do you think about Blacktime Freddy? Do you have any

Charlotte Emily, Five Nights At Freddy's Wiki

Shadow Freddy FNAF Guide - FNAF Insider

The Twisted ones but they're based on the novel's descriptions

The wiki says that Shadow Freddy appears in The Twisted Ones Novel

The bite victim is shadow freddy (personal theory/semi headcanon

FNaF Movie, FNaF: The Novel Wiki

RWQFSFASXC, Villains Wiki

FNAF Easter Eggs to Find - FNAF Insider

William Afton, Five Nights At Freddy's Wiki