Disclaimer: I do not own the character's from the Grim Adventures of Billy and Mandy, nor do I own the Mirror of Erised.

A/N: This idea came to me after I was finally able to locate Billy and Mandy's Big Boogie Adventure on the net. I hadn't seen it before then. Anyway, this was inspired after watching the scene where they all face their fears trying to get to Horror's Hand.

This is just a small one-shot... that seems to be all I can write for Billy and Mandy.

"Hey Grim!" cried Billy, jumping on the couch excitedly. "Whatcha wanna do today? Oh! I know! I know! Let's play opposite day again! We can walk around town backwards and order breakfast for dinner and, oh! Oh! We can wear shoes on our hands! Come on Grim! Can we? Can we? Canwecanwecanwecanwecanwe?? "

The Grim Reaper, reaper of the dead souls of the deceased, controller of life and death itself, moanded in agony. "Not today, Billy, I've got de worst headache mon. I was out late reaping again and didn't get any sleep because you were singing in your sleep... again."

"Huh? I don't remember that!" Billy ceased his jumping and stood still on the couch. "Do I have a be-oootiful voice?"

"No, Billy. You sound like a cat dat's been put through a dishwasher."

"OhohOH! I remember when I did that once to Milkshakes! She came out all soapy and wet with bits of food stuck in her hair. I still gots the scars she gave me when I tried to give her a sorry-hug."

"You truely are one heck of an idiot, child," said Grim wisely, scaning through the channels with the TV remote.

"Yeah, I know!" said Billy with a goofy grin on his face. "Hey! Can I go play in your trunk?"

"NO!" Grim boomed. "How many times do I have te tell ya, stay out of me trunk!"

"Aww, c'mon Grim! I'm bored!"

"What are you dweebs moaning about?" a sever voice came from the doorway.

"Mandy!" cried Billy excitedly. "You will play with me, right?"

"Think again, Billy," said Mandy indifferently, crossing the rom and sitting on the couch next to Grim. "I'm tired and I don't want to deal with your idiocy right now." Billy's head drooped in disappointment.

"What's de matter wit you?" Grim asked.

"Irwin keep me up last night. He's been serenading to me again," she snatched the remote from Grim so she was in control of what was to be watched. "And then today he was following me around in that stupid teddy bear suit."

"I don't even know what the heck dat boy see in ya," said Grim, earning himself a punch to the head.

Ding dong!

"Billy open the door," Mandy commanded. "And if it's Irwin don't let him in!"

Billy opened the front door and sure enough there was Irwin, standing there in his white fluffy teddy bear costume.

"Sup, yo?" said Irwin, casually placing his arm on the doorframe with his weight leaning on one leg.

"Irwin, you have no friends, so you will play with me, right?"

" Sorry, yo. I'm just here to see my woman."

"Your what?"

"My girl yo! That luscious Goddess that invokes such love and passion into my heart I feel it may explode each time I set eyes on her!"

Billy scratched his head with uncertainty. "You think my mom is a goddess that makes your heart explode? Coz I don't think she'd like you callin' her delicious, she thinks she's getting fat."

"Not your mom!" cried Irwin in frustration. "I'm talking about Mnady!"

"Oh," said Billy with disappointment. "She's watching TV."

"Thanks Billy. Scuse' me while I go and get my groove on," Irwin wiggled his eyebrows at Billy and confidently walked into the living room, wearing his teddy bear costume.

Billy heard: "Sup Maaaaaaan-day... how's about givin' your Romeo a little sugar?" and then a violent CRASH and "My bad, yo."

Billy sighed. "I'm so bored! And hungry!" Billy walked into the kitchen where Gladys was busy cooking.

"I'm hungry!" Billy announced.

"Not now, sweetie, Mommy is busy baking pie for later,"

"PIE!" shouted Billy happily, he began to run circles around his mother.

"Piepiepiepiepiepiepiepiepiepiepiepiepiepiepiepie!"

"No Billy!" cried a very stressed out Gladys. "You can have some pie later!"

"But I want some now!"

"Billy, go and play somewhere... anywhere!"

Billy stopped and thought about this. "Anywhere, eh?"

Several minutes later Billy was searching through Grim's trunk. "There's gotta be something to do in here. Whoa!" Billy lifted a large bulky object out of the trunk. "I wonder what this is? Grim will know!"

Billy dragged the object back into the living room. "Hey guys! Check out what I found! Pretty neat, huh?"

Grim and Mandy regarded the object wearily. "Billy, did that come out of me trunk?"

"Ye-NO!"

"Why you lying little... How many times have I told you te stay out of me trunk?"

"I stopped counting after the nineteeth time," said Mandy indifferently. "So what have you found this time, Billy?"

"I think it's a... a... a..." Billy paused for a minute. "A kangaroo?"

Mandy punched Billy. "Stop being an idiot."

Grim took the large object and leaned it against the wall. "It appears to be a mirror."

"What's that inscription say?" Mandy pointed at a carving around the curved top of the mirror.

"Erised stra ehru oyt ube cafru oyt on wohsi," Grim read.

"What does that mean?" asked Billy.

"To hell if I know," said Grim, shrugging.

"Well you should know," snapped Mandy. "It was in your trunk, Bonehead!"

"How am I supposed ter keep track of all de tings I keep in me trunk? I have half of de Underword livin' in there!"

"So I assume this mirror is going to do something, then?" asked Mandy.

"Only one way ter find out," Grim stood in front of the mirror and stared at his reflection. "That's strange," muttered Grim.

"What's the matter, yo?" asked Irwin nervously.

"My reflection appears to be holding me scythe, but me scythe is in de umbrella stand."

Grim looked at his reflection again. This time Billy and Mandy were standing beside him. The Grim in the mirror raised his scythe and swung it...

"BWAHAHAHAHA!!" Grim began to laugh maniacally.

"Hey Grim! What's so funny?" asked Billy excitedly.

Grim didn't answer but continued to laugh with his reflection at the deaths of Billy and Mandy.

"Alright Bonehead, fun's over," Mandy punched Grim in the jaw and brought him to his senses.

"Your turn, Irwin," said Mandy.

"What? Why me, yo?"

"Because I said so," Mandy shoved Irwin towards the mirror.

Irwin approached it cautiously. In his reflection he appeared to be much older, much more handsome and very, very cool. Beside him stood a beautiful blonde woman with a dazed look on her face, and a strange smile, her hair was the shape of a pair of devil horns. The two people in the mirror were dressed in wedding-wear. A suave and handsome tuxedo for Irwin and a beautiful and revealing white dress for the woman beside him.

"I'm marrying Mandy, yo!" exclaimed Irwin with pure happiness.

"Eh?" said Billy.

"What?!" said a shocked Grim.

"I think I'm going to puke," scowled Mandy.

"It's true, yo! It's all here," Irwin turned to Grim hopefully. "Grim, do you think this mirror shows the future, yo?"

"Ooh! I certainly hope so," said Grim, happily remembering what he saw in his reflection.

"Out of the way, dweeb," Mandy puched Irwin away from the mirror. "Tim to see what this mirror's really about."

Mandy looked at her reflection and was instantly mesmerised by what she saw. Thousands of people, no... it was millions of them. Millions of slaves and servants bowing to her, chanting her name. And there stood Mandy, exactly the way she was now, without being a giant slug-like creature (referring to the epp. Mandy the Merciless). Just Mandy, in complete and utter control over everything.

"Yes..." Mandy whispered in awe, pressing her hands upon the glass, as if hoping to fall into the world before her.

"My turn!" cried Billy and tackled Mandy from her position infront of the mirror, breaking her trance.

"Billy you idiot! I wasn't finished!"

"You had your turn!" Billy blew a raspberry at her and looked in the mirror.

He stared at it for a few seconds.

"What do you see, Billy?" asked Irwin.

"I see Grim and Mandy standing behind me," said Billy. He turned around and saw Mandy and Grim standing behind him. Billy waved at the mirror, his reflection waved back. Billy picked his nose, his reflection picked his nose.

Mandy grew impatient and slapped him. Billy's reflection was slapped by Mandy.

"Grim! It's not working!" cried Billy.

"What do you mean it's not working?"

"It's not doing anything special. It's acting just like a normal mirror. If I wanted to look at a norma mirror I'd go to the bathroom!"

"Good one, Billy." said Mandy angrily. "You broke it and all you had to do was look at it!"

"Yeah! Thank's a lot Billy!" scolded Irwin.

"Billy!" called Gladys from the kitchen. "The pie is ready!"

"Pie?" Billy instantly forgot everything about the mirror.

"Piepiepiepiepiepiepiepiepiepiepiepiepiepiepiepie!" Billy abandoned the mirror and ran into the kitchen.

Mandy and Grim looked at each other, shrugged and follwed him in slow persuit, with Irwin trailing behind him.

"Now, can you think what the Mirror of Erised shows us all?"

Harry shook his head.

"Let me explain. The happiest man of earth would be able to use the Mirror of Erised like a normal mirror, that is, he would look into it and see himself exactly as he is. Does that help?"

Harry thought. The he said slowly, "It shows us what we want... whatever we want..."

"Yes and no," said Dumbledore quietly. "It shows us nothing more or less than the deepest, most desperate desire of our hearts."

-Extract from Harry Potter and the Philosopher's Stone.