Felix:
He is the easiest animatronic by far, as by booping his nose, he goes back to stage.
Felix is programmed to free roam, as he is a waiter and he is responsible with delivering sweets to tables, along side Madison who has the same program.

His fur actually hides a speaker on the back of his neck.

In the cartoon version, Felix is actually described as energetic and chaotic yet still friendly

Nightguard 2#:
He went missing on the 3rd night.
The most stitches are on his forehead so you can get the idea what happened to him.
He was the first who actually called on the 3rd night, telling at Max to call the boss or the police because the animatronics are hostile