She can talk. If Mangle had a soul of dog, she would be only able to bark, whine, etc.
She moves on "all fours". But how to hell this is connected to a dog? Mangle was broken down. She is supposed to move like that, because of rearranged body parts
Dog died even earlier than Mangle was built. The dog belonged to a girl, called "Susie". As we know from Fazbear Frights, Susie is one of missing five children, a soul which posseses Chica. And also we know that William killed his 5 victims before fnaf 2. This means the dog was killed in the same time with Susie (or even earlier), and it`s soul just couldn`t reach Mangle, who was made years after.
So, Mangle is not possesed by a dog
P R O V E N

5 years ago
Proofs that Mangle is not possesed by a dog
Next up
[Blender/Fnaf] Molten Freddy in the back alley
[Blender/Fnaf] Glamrock endo custom night icon
[Blender/Fnaf] Moondrop custom night icon
Fix Fredbear
[Blender/Fnaf] Glamrock foxy custom night icon
He's gonna getcha!
[Blender/Fnaf] Golden Freddy custom night icon
[Blender/Tjoc] Endo B "Angel' custom night icon
The Fredbear and Springbonnie cutouts are here!!Huge shoutout to @/damp_swan on Twitter go check out their awesome art!
[Blender/Fnaf] Jetpack BB custom nignt icon










6 comments