Sammy

Warning: This won't be updated with all of the information from the new novel until some date after the UK release."[ 'She heard the toy truck hit the ground and spin in place for a moment, then everything was still.' (Charlie's flashback of Sammy being taken). ]"

Sammy
Sammy is Charlie's brother and Henry's son. He is never present in the novel, as he is abducted at the age of 3 by a man in the yellow rabbit suit who is later revealed to be Dave Miller, otherwise known as William Afton: Henry's business partner.

Charlie starts having nightmares after what happened at Freddy's, but she also starts feeling another presence, as if she isn't alone. She believes that Sammy's spirit is with her. But comes her birthday, which is also her twin brother's birthday, she feels as if he has been parted from her as if trapped in a box or sealed behind a closed door.

All over her school notes, Charlie started drawing dark rectangles, which later turned out to be doors. Sammy's presence was hinting at her about a door, and she knew it had to be back at her father's house. Later in the book, she locates the door, but opening it would result in her death. The door is never unsealed.

Appearance
Sammy's appearance isn't described, but being Charlie's twin brother, they likely would have a lot in common.