Today was William Afton's favourite day of the year.
He had spent his time in the backstage area of Fredbear's Family Diner the night beforehand, eagerly establishing his 'play-area' for the day that faced him. He was itching with excitement, the sensation causing him to rake his chapped nails across his pale arms at an alarming rate.
Soon enough, his arms were coated in red scratch-marks, accompanying his spring-lock scars, but the gaunt man did not care. He was simply too excited!
He did not even care about the looks of concern his colleagues flashed him as they walked in to start their shifts, meeting their furrowed brows and downturned mouths with a near-manically gleeful grin. Rubbing his eyes to rid himself of his dreadful tiredness, hearing the soft squelching of his eyeball from the force with which he pressed his own palm to his socket, William practically skipped over to his prized possession - and, now, his tool for the greatest joke he'd ever pull!
All else ran as it usually did in Fredbear's, save for the occasional instances of children tricking one another in good-hearted whimsy. Fredbear himself, a portly animatronic bear of a rich golden colour, swivelled about on his stage, filling the building with jovial music and corny jokes.
One child sat in the corner of the room, alone. However, he held a face of contentment regardless, simply happy with cranking the music box he held in his hands - the sweet, tinny music served to calm him, and his sheet-white face glowed a slight rosy colour as happiness filled him.
Another small group of children clambered beneath tables and around startled parents, laughing and tittering as they played a game of It. A young boy, his face painted to resemble a golden rabbit, giggled as he chased his excited friends with an arm outstretched to catch those who could not outrun him.
Even the day-guards were occupied in their own form of entertainment on this joyous day, pulling fast ones on one another and attempting to deceive each other with harmless pranks.
William watched all of this transpire from a crack in the backstage door, pressing a yellow eyehole right up against the cold material of the entryway. He shuddered with excitement, anticipating the fun he was about to have, before leaving the room with a confident gait.
Suddenly the wild-eyed excitement was gone, and all that was left was a jolly and energetic golden bunny. Bonnie walked along the back wall of the large room that made up the main room of Fredbear's, looking to each group of children occupying the establishment. Soon enough, he'd spotted an ideal candidate for his prank of the century, and he had to stop himself from trembling with eagerness.
The young child in the corner of the room took note of a large figure bounding towards him, looking up and into the shadowy eyes of Bonnie the Spring Bunny. Lowering his music box in wonder, the child smiled at the friendly sight.
"Hey there, friend!" Bonnie began, an unsteady Southern drawl occupying their uneven high-pitched voice. "Why're you all alone over here? Don'tcha have any friends to play with?"
At this, the child simply shook their head sadly, looking back down at the ground for a moment.
Bonnie had to hide the grin overtaking his face, clamping the mouthpiece of his suit shut tightly.
"Well, I got an idea! Howzabout you play with me? I'll be your friend!" He continued, his voice seeming to tremble even more now.
At this, the child immediately perked up. Nodding vigorously, he clambered onto his feet in but a moment, still clutching his music box close to his side. It continued playing its gentle, lilting melody.
Bonnie clasped his hands together eagerly before gesturing for the young boy to follow him, stating "I know an awesome place where we can play together! Come along n' follow me!"
And so, as Bonnie began walking back to the backstage room, the child obliviously followed their command.
He pondered showing his mom his new friend, before deciding that he wanted to see Bonnie's cool play-area first.
The tall rabbit hurriedly ushered the boy beyond the door to the backstage area, the room being much colder than the rest of the building. The child immediately noticed a change in mood, with the room being an industrial grey rather than the warm golden hue that filled the rest of the establishment.
He heard the door click shut behind him.
He just about managed to turn around, seeing an exceedingly lanky black and white figure laid out on a workbench, before he felt a sudden jolt and stared into the empty eyeholes of Bonnie the Spring Bunny.
He didn't acknowledge the presence of the knife in his neck until he felt a burning pain, and realised that he could no longer breath. An abnormally strong hand gripped him tightly, keeping him in place, as his music box fell from his hands - even now, with warm blood spattered along its six faces, it played its song.
Now Bonnie, too, was covered in blood, and suddenly he wasn't Bonnie anymore.
William peeled back his suit head, the long bunny ears of the mascot flopping against his back, as he flashed the dying boy standing on quivering knees before him with a radiant grin. Teeth stained with neglect and coffee revealed themselves from behind his thin lips, and a scar left a substantial patch of his upper jaw exposed even with his mouth closed. Here, his gums were purple and cracked from a lack of moisture, the teeth here being even further neglected.
One brown eye and one grey one bore into the now-stilling boy, who, despite panicked gurgles, simply could not stand on his own two feet anymore.
Falling into William's arms, the man cradling the boy lovingly, he finally shut his eyes for the last time in his life.
William, still rocking the child steadily, leaned his blood-spattered face in close to the boy's own one, the pair being coated in the child's gore, and licked droplets from his own exposed patch of scarred gum. He revelled in the victorious sensation of knowing his prank went perfectly, giggling gleefully to himself, before leaning in ever-closer.
He pressed his lips up against the boy's cold ear, and whispered a phrase that had given him oh-so-much joy throughout his long life, only being able to utter it once every year.
"April Fool's."