GENERAL

Four bored marauders (one of them incapable of speech because of a, uhm, potion) sat at the back of the class and tried to amuse themselves the best they could during Defence Against the Dark Arts, trying not to get noticed by Professor Malfoy.
It was one of those theoretical lessons where the students had to answer questions from their book on their own, and since Remus always tried to be a couple of chapters ahead everybody else, he had been kind enough to share the correct answers with his friends and thus leaving them some time to work on their Snape-art.
"I know I said there's no such thing as too big an ass" said James, observing their work in progress. "But now the head is hidden! How can we tell it's Snape?"
"No problem, I'll just add some greasy hairs to his buttocks" Sirius drew some lines on both cheeks. "But the question now is: What are we gonna do about the nose we can no longer see?"
Both James and Sirius stroke their invisible beards. Remus glanced at the picture and simply drew the nose on the crack.
James and Sirius beamed, nearly crying from pride.
"Moony you're a true artist!"
"Thanks, but I already knew that"
Suddenly, before any of them had time to react and hide the portrait, it was lifted to the air and caught by Professor Malfoy.
"Well, well, what's going on here then?" he said. "500 points from Gryffindor for not paying attention in class"
"What were we supposed to pay attention to?" James argued.
"Another 500 points for being you"
All the rest of the Gryffindors glared at Lucius, but he just looked at the picture for about a second. Then he started laughing so hard he returned the taken points, added a thousand, dismissed the class, framed the drawing and put it on his desk.

As usual, Remus went straight to the library to do some homework. James and Sirius went there too, followed by Peter, because they wanted to work on the map-insults.
"So in case this map gets lost, one of a thousands people may find it" said James, tapping his quill against the table. "There's no way we can write personal insults for a thousand people"
"I'm sure there's some spell that makes the insults write themselves as if they came straight from our heads" Sirius swinged his legs restlessly from where he sat at the top of a bookcase.
"Uhm Mr Prongs wonders for what exact purpose would somebody already have invented a spell like that, stupid"
Sirius threw a book in James' head. "Mr Padfoot would like to suggest that there must be loads of situations where such a spell could come in handy"
"Mr Prongs dares Mr Padfoot to name one"
"Er Mr Padfoot would like to think about it"
"Mr Prongs gives Mr Padfoot 3 seconds"
"Mr Padfoot wonders who Mr Prongs thinks he is, the time police?"
"Mr Prongs takes that as Mr Padfoot can't think of a situation"
"Mr Padfoot wonders who Mr Prongs thinks he's fooling, calling himselfMr…"
"Mr Prongs would like to warn Mr Padfoot for he is about to kick his ass"
"Mr Padfoot is getting bored waiting for Miss Prongs to bring it on, the pansy"
And then Mr Prongs did bring it on. And while he and Mr Padfoot were tumbling about among the books, Mr Moony had gotten inspired to invent a spell that would automatically insult whoever would come across the map and started browsing through potentially useful books. Done bringing it on, James and Sirius decided to help out.
"Remember, guys, I don't want Lily to be insulted by anyof us in case she happens to come across the map" said James.
"You're not the boss of my insults" said Sirius.
"Seriously, I'm warning you!"
Sirius frowned. "Oh are you now? Well in that case, I have a girl I'd like to be free from insults as well"
"Who?" James glared at him.
"Dorcas"
"You are so immature! Only because she and Lily had a big fight!"
Sirius shrugged. "What can I say? She's the love of my life!"
"Yeah right, that's why you broke up with her, and NOT because one of her ears is slightly bigger…"
"It takes love to notice details like that, you know"
James turned to Remus for support.
"Moony tell him off!"
"You do realize you're both prats?"
"Mr Wormatil is hungry" Peter squeaked randomly.
"Go eat then"
Feeling somewhat neglegted, Peter trotted out of the library.
Silence followed. The remaining marauders found a way to make the map insult pretty much everybody in the world that at least worked in theory, but since it involved some complicated magic they couldn't try at the moment, at least Remus continued with his homeworks.
"I'm bored" said Sirius after what felt like hours but really were two seconds. "Let's go on a adventure!"
His friends thought that was a jolly idea.

(A/N: Right, what can I say? I hope you enjoyed this part enough to stay tuned! As you migh have guessed, the next part will be written in adventure style. Ish. Queen rules, by the way! Ask Sirius!)