fnaf 4 fnaf 3 and the books confirm there was a big springbonnie and small springbonnie since springtrap was the small one and the books have a two big springbonnie which looks allot like the big springbonnie head we find in fnaf 4 which means that into the pit is just a demon using a springbonnie suit which means it isnt stuck in it and the bigger suits are better and used more cus the space leaves more room and that causes that even if people do something that can enable the springlocks it has less chance to lead to it which is part of the reason william was bound to be springlocked cus he put on a smaller one thats verrry close to his body