A fanfiction could explore the relationship between Foxy and Mangle in a more emotional way. Maybe Mangle has always been in awe of Foxy's courage and Foxy starts to see Mangle in a new light, leading to a deep friendship or something more. It could be set during a particularly difficult night in the pizzeria when they have to rely on each other more than ever.
In FNAF fanfiction, FunTime Foxy and a male OC can create really interesting stories. The male OC could be a new night guard, for example. He might start off being scared of FunTime Foxy but then gradually understand the animatronic's true nature. This could lead to a unique friendship or an adventure where they face other threats in the spooky world of Freddy Fazbear's Pizza together.
Definitely not a true story. FNAF is a work of fiction that takes place in a fictional world with its own set of rules and scenarios. It's all about creating a thrilling and immersive gaming and storytelling experience, not reflecting reality.