A/N: Just a blurb of an idea. Not sure where the plot bunny came from, but I hope you enjoy. Please leave a review!

Gravity Falls belongs to Disney. Rise of the Guardians belongs to Joyce & Dreamworks

Pitch Black

A.K.A. 'The King of Nightmares'; 'The Boogeyman'

The Destroyer of:

Pleasant Dreams

Special Power:

-Materialize/dematerialize as shadows

-Stealing children's happy Dreams and replacing them with Nightmares

-Feeds on Fear of individuals

-Invisible to most human adults and disbelieving children

Known For:

Trying to take away hope and joy for all children.

Weaknesses:

-Sandman's dream-giving sand

-Sunlight

-I do not know anything else that can be used to defeat the Nightmare King.

The origin of the Nightmare King is unknown to me, perhaps even to Pitch himself. As old as time, Pitch Black has been the monster lurking under the beds of children and the fuel for their nightmares for eons. He may be known as the Boogeyman now that western culture has caught up with him, but he is a force to be reckoned with. The living embodiment of Fear itself, Pitch Black has only been known to be defeated by the power of Dreams, possessed by the Sandman.

It is impossible to evade the Nightmare King. This is a simple fact. He can smell fear, revels in it, and it grows at his behest. Be warned, Pitch Black's powers are effective, even to a non-believer. I have fallen victim to the force of his Nightmares, and now, whosever reads this accursed book, be wary. Pitch's Fear may be strong, but so are the beasts residing with Gravity Falls.

"Mabel! Mabel, hurry up!" Dipper panted as he and his twin sprinted deeper into the forest and away from the monster pursuing them. His speed was hampered by the Book as he struggled to open it and find the correct page.

"I'm right behind you, Dipper!" Mabel gasped, her chest heaving similarly to her brother's. A crash echoed behind them, and a massive oak began to fall toward them. Mabel looked behind her just in time to move out of the way and yank Dipper with her.

"Thanks!" he puffed, keeping his hat from flying off his head with one hand as he continued thumbing through the Third Book, only looking up long enough to avoid any upturned roots or stones.

Mabel risked a glance behind her, shuddering when her gaze caught the slimy, green hide slithering furiously toward them. She doubled her speed, looking at her brother now.

"Dipper, how do we get away from this thing?"

"I'm working on it, Mabel!" Dipper wheezed shrilly, finally releasing an exclamation of surprise as he as he stopped rifling through the Book.

"Found it!" Dipper announced in relief, and began reading aloud as the monster released a blood-curdling roar into the air. "'The basilisk is known as the "king of the serpents', hatched by a rooster from the egg of a serpent or toad'-"

"Dipper!" Mabel hissed, and the sound of crunching branches and tree trunks came nearer.

"Okay, okay!" Dipper panted, skipping to a paragraph further down the page. "'The basilisk's odor is said to kill snakes, fire from its mouth kills birds, and one glance will kill a man. Avoid at all cost'- yeah, thanks!"

Mabel whimpered from behind him, and Dipper reached back with to grasp his twin's hand. She inhaled sharply, pumping her legs to keep up with him.

"How-how do we beat it?"

Dipper risked a glance back down at the Book. "'Only a weasel can kill a basilisk.'"

Mabel groaned from behind him. "How are we gonna find a weasel!"

Dipper panted, opened his mouth to answer, and closed it again. He stopped suddenly, and Mabel's hand was wrenched from his grip as she ran on in surprise.

"We can't," Dipper said. "We can't beat it."

Mabel ran back to her twin's side, gasping for air. "What're you talking about, Dipper?"

"It can only be killed by a weasel," Dipper repeated, holding up the Book in defeat. "There's no way we can beat a basilisk."

"Dipper-"

The basilisk shrieked again, and the oaks around them shook. Dipper turned to gaze imploringly at his twin, reaching out to her with one hand. Mabel stared at him in shock and denial for many seconds, before she gripped his hand again, tightly entwining their fingers.

"It's been fun, little bro," she said evenly, her fear only evident by how tightly she held her brother's hand.

"It's too bad we never fought any actual zombies," Dipper agreed, and they both flinched as the basilisk uprooted more trees, the slithering sound and stench that accompanied it growing nearer.

Mabel nodded shakily. "Yeah. Soos was really looking forward to splattering zombie brains."

Dipper pressed the Book tightly against his chest, so maybe when the basilisk found them it would be destroyed with them. He would not wish their fate on anyone else unlucky enough to find it.

The beast roared again, only a few dozen feet away, and Dipper turned his head toward his sister.

"Hey, Mabel...I'm sorry."

"For walking up the basilisk, or telling me it was harmless in the first place?"

Dipper chuckled weakly. "For...all of it."

"Oh." Mabel blinked once before shrugging. "Well I forgive you."

As the basilisk broke through the tree line at last, Mabel pouted slightly.

"Grunkle Stan better take care of Waddles while I'm gone."

The children scarcely had time to flinch before the basilisk pounced, it fangs bared and dripping with venom, and it released a tremendous screech upon finding its prey.

With their eyes screwed shut, Mabel and Dipper did not witness the sudden mass of black substance erupt from the basilisk's shadow and fall smoothly before the children like living, ebony water, stopping the beast in its tracks.

When neither felt even remotely skewered by those fearful fangs, the twins carefully opened their eyes to see a veil of darkness surrounding them, with the sound of the basilisk whimpering behind it.

"What the...?" Dipper breathed after a moment of stunned silence, and the ebony veil shivered once. The basilisk released a howl not unlike the sound of nails on a chalkboard and the twins winced. Then, they heard the soft whispering sound as the basilisk slithered away, and all was quiet.

"Dipper..." Mabel whispered, as if anything louder would bring the basilisk back. "What just happened?"

Before Dipper could even consider any form of answer, the black boundary suddenly collapsed in on itself, forming something new in front of them. In mere moments, a man with skin so pale it was nearly gray stood before the brother and sister, who still held each other as they had done when the basilisk was advancing on them. His long robe seemed to be made of the very ebony substance that had protected them seconds ago, and silver-gold eyes rested in a thin face with high cheekbones. These same eyes were focused maliciously on the twins.

"Such terrified faces," the man said sorrowfully, "so sad to think that I was not the one to cause such fear."

Mabel's tightening grip on Dipper's arm threatened to cut off his circulation, but he paid it no mind as the robed man stared down at them from his advanced height, waiting for them to answer with a lifted brow.

The twins inhaled in unison, and the same time asking "who are you?" and "why did you save us?"

The man bent his shoulders back, standing up straighter as he clasped his hands behind him.

"Ah. So you can see me. What a relief. Here I thought it was all for nothing." He circled them once, like a predator stalking his prey, and Dipper raised his gumption and his chin to demand answer.

"Why did you save us?" he asked again, more firmly now. Mabel, although still very pallid, seemed to draw courage from her brother's own reserves, and met the strange man's gold-flecked eyes with an even look of her own.

"Well I could bring the basilisk back if you really want me to," the man said with a shrug and a shark like grin.

Dipper flinched.

"But...how did you even get rid of him?" he went on to ask.

The man bent his long, bony fingers to resemble claws. "I scared him off."

"How?" Mabel asked him softly.

He groaned. "Why do you ask so many questions?"

"We're kids," Mabel shrugged, her voice gaining strength, though she still did not release Dipper's arm, "we're naturally curious."

The man grimaced. "I am beginning to regret rescuing you."

"Then why did you?" Dipper countered, and returned Mabel's crushing hold when the man trained his golden gaze directly on them.

"Do you know who I am?" he whispered dangerously, and he began circling them again.

"A creepy loser who needs to go out in the sun more?" Mabel guessed bravely.

The man sneered.

"No." He bent his neck to look at Dipper."What about you, boy? Have you read about me in that book of yours?"

On instinct, Dipper clasped the Book more firmly against him.

"It depends," he retorted warily."Who are you?"

The man grinned suddenly, revealing pointed teeth.

"Oh, I am certain you have heard of me. I have been known to hide under beds in the past."

Dipper went white as a sheet, though Mabel's gaze flickered between the two uncomprehendingly.

"Pitch Black," Dipper whispered, to the concern of his sister, and the unabashed glee of Pitch, who appeared to gain substance before them, growing stronger at the mere mention of his name.

"In the flesh," Pitch leered, bending over in an extravagant bow.

Dipper swallowed, worriedly going over the information he had gleaned from the Nightmare King's pages in the Book.

"The Boogeyman?" Mabel suddenly gasped, realization striking her over the head like an anvil. "You're the Boogeyman?"

Pitch beamed, showing his jagged teeth once more.

"Ah, another avid fan! I have been keeping an eye on you, Mabel Pines."

The twins froze at the utterance of her name.

Confusion and concern twisting on her face, Mabel stammered, "H-how-how did you know who I am?"

Pitch loomed ponderously over them, his features shadowed.

"I make it my business to know."

"Oh yeah?" Mabel declare brazenly, despite her brother's quiet protests. "Then what did I-"

"-Eat for breakfast this morning?" Pitch finished lazily for her. "Pancakes with-" he grimaced "-'Mabel' syrup."

Mabel's eyes widened to the size of saucers and the grin returned to Pitch's face.

"You see, my dear, as the embodiment of fear itself, I am granted...shall we say, certain 'liberties' when it comes to the psyche of humans. Meaning..." he moved fluidly, and in the blink of an eye the only sign that he had shifted position at all was his sudden presence a few scant inches from Mabel's terrified face. "I can look into your mind," he finished sinisterly, clearly enjoying the amount of fear he was capable of instilling in the young girl.

"Hey, back off!" Dipper shouted, swinging the arm that held his Book at the Nightmare King, only for his arm to pass through Pitch as if he were nothing more than mist. As Dipper blinked in confusion, Pitch cackled.

"Oh, you two are fun! Most children run screaming but you two! No, you have seen so many horrors, fear is familiar to you."

"I-is that why you saved us?" Dipped demanded, straightening in the face of Fear. "Because we amuse you?"

A puckish look appeared on Pitch's face as he stepped back.

"Partly," he admitted truthfully, "but you and your sister are...different. You stand tall in the face of death and unimaginable fear, unblinking and unerring. It's...admirable."

"Well...thank you," Dipper responded, his eyes not leaving Pitch's as he reached for his sister's hand, which Mabel provided willingly. "But we'd better get back home now. I think I can hear Grunkle Stan calling us."

To both Dipper's surprise and relief, Pitch did not try to stop them. He and Mabel walked quickly, her hand clasped in one of his while the other held the Book with white knuckles. They did not get very far, however, when Pitch's lofty voice wafted toward them.

"Ah, yes...Your Great Uncle Stan Pines...he certainly has some interesting nightmares."

Dipper froze mid step, he and Mabel exchanging an anxious glance before looking over their shoulders at the Boogeyman standing in the middle of the forest, like a dark blot against the lush vegetation.

"What do you mean?" Dipper demanded his tone braver than he felt. Pitch grinned wickedly.

"Oh, I'm not too sure your 'Grunkle' would like me spilling the beans just yet. I'm sure the story will be more interesting coming from him."

"Stop being stupid!" Mabel ordered, turning fully to face the silver-tongued man. "What are you talking about? What's Grunkle Stan's big secret?"

Pitch chuckled throatily.

"Well, well, Miss Pines, I was wondering when your fabled temper would flare. And I must say again- it is not my secret to tell."

"Then why even bring it up?" Dipper commented suspiciously.

"Perhaps I enjoy manipulating the minds of children," Pitch retorted with a leer. Dipper scoffed, turning back around and pulling Mabel along with him.

"You're just talking in riddles. C'mon, Mabel, let's head back to the Shack."

Mabel complied, though not without sticking out her tongue at Pitch.

"Have a nice rest of the evening, children!" Pitch called to them, his words palpable even as they put more distance between themselves."I look forward to seeing you again soon, Dipper Pines!"