They'd originally stumbled across the spell at one of their book club meetings, aimlessly flipping through books they found in the library while chatting about nothing in particular.
Lily sat up abrubtly, causing the other two to jump and look at her curiously.
"What did you find?" Regulus set his book on his lap.
Lily looked up at them both with a huge smile on her face and a hint of hope in her eyes, "So I found this thing.." she trailed off, looking nervous.
"Lils?" Remus leant forward and placed a hand on her shoulder in what he hoped was an encouraging gesture, Regulus shuffled closer to her other side.
Lily took a deep breath, releasing it before speaking, "It's the animagus spell, and I kind of want to try it?"
Remus nodded, "Sounds cool, I'm in."
Regulus hummed in agreement, "What's the first step?"
Lily flushed slightly, " Here's the thing though: we have to register if we're successful though."
"When we succeed you mean, and let's just not get caught then." Regulus shrugged and closed his book.
Lily ran her finger down the list of ingredients, "Okay, Rem you try find a sticking charm, Reg here's the list of ingredients and I'll work out the time frames."
Grinning, they set to work.
Regulus came skidding into the library, his eyes bright and a huge smile on his face, "Rem, Lils!"
A loud hush came from the desk where Madam Pince was sat.
"What is it Reg?" Remus patted the seat next to him.
Regulus shook his head and started tidying away the homework and books that littered the table, "Storm." Was all that was ended to be said for them all to shove things in their bags and run for Remus' dorm.
They finally arrived, gasping for breath as they burst through the door, startling Sirius and James who were sat on the latters bed reading magazines.
Lily went straight to Remus' trunk and flung the lid open to pull a wooden box out, she handed it to Remus, who nodded and ran out of the room with Regulus not far behind.
After slamming the lid, Lily stood up and, after nodding at the two shocked boys, ran after the other two.
James ran a hand through his hair and turned to Sirius, "What do you recon that was?"
"Dunno mate, probably homework or something."
They both shrugged and continued reading.
After they'd all arrived in the room of requirement and Lily had shut the door she spun around and took the vial that was handed to her.
Remus smiled, "Cheers." Lifting his vial in a toast, the other two laughed and did the same.
In unison they tipped their heads back and drank.
After a few grunts of pain and surprise they all found themselves looking at the world on a much lower level.
Turning to see what the other two were Regulus was met with the sight of two cats.
One was a fairly average sized ginger cat with white stripes, "That has to be Lily." He thought.
The other was a large brown striped maine coone, Regulus snorted in amusement before looking down to try and see what he was.
Small black paws and black fur: a black cat, apparently a small one too.
Unable to help himself, Regulus started laughing uncontrollably.
All of a sudden he was human again, laying on the floor in fits of hysterics.
Sitting up he came face to balls of fluff, seems the other two decided it would be fun to jump on him.
He swatted at them, causing them to devolve into a friendly scuffle ending with Regulus laying on the floor again with two lumps of cat on his stomach.
"Right come back now, I want to gossip."
Obliging, Remus and Lily climbed off of him and turned back into their human selves.
Lily was the first one to speak, "I can't believe we're all cats, how great is that?!"
They all had an excited gleam in their eyes as their success became reality.
"That potion tasted disgusting though." Regulus grimaced at the memory of the taste.
Remus nodded, "Yeah it was vile, get it?"
Both Lily and Regulus groaned and slapped him on the shoulder.
Remus' smile widened, "Guys, I'm not a wolf!"
He was enveloped in a hug.
By the end of the evening their cheeks would hurt from the amount they were smiling.
"Let's hope we don't get caught."
1.
Since becoming animagi they'd made the agreement not to tell anyone, not even their other friends, it was their secret.
It was past curfew, meaning the halls were empty, dark and quiet.
As a group they'd started taking walks around the castle as cats every other night in order to get used to their new bodies, but also to get the chance to hang out.
For that evening the three of them had settled in the Gryffindor common room by the fire, all laid out in a cuddle pile.
They'd only been like that for about 35 minutes when they heard the sound of footsteps coming down the stairs.
Immediately they all turned back into humans but stated laying on the floor by the fire.
Just in time as well, James, Sirius and Peter all came bounding down the stairs and towards them.
"You alright?" Remus opened an eye to look at them.
Looking a little sheepish Sirius scratched the back of his head, "Yeah we were just wondering where you were."
Answering with a hum Remus sat up, causing the two who were using him as a pillow to groan in annoyance.
With a fond smile he tapped their shoulders lightly, "Come on guys, we should probably go to bed."
He pulled them into sitting positions and heaved himself up.
After stretching he noticed that they had managed to stand up.
"Reg do you want us to walk you back?"
"No it's fine Rem, see you guys tomorrow." He leant forward and gave Lily a kiss on the forehead, receiving one in return, before gesturing for Remus to lean down so he could do the same to him.
Remus leant down and accepted the kisses from both, before returning the gesture with a smile and a hand in their hair.
He missed the slightly jealous looks the other three were sporting as he followed them up the stairs to their room.
2.
A couple of days after nearly being caught they were stretched out on top of a wall outside soaking up the sun.
It was a Saturday so there were no lessons, allowing them to take advantage of the summer sun in cat form.
Many people had already walked below without noticing them,it just had to be their friends that noticed them.
Though that may have been because a wasp flew nearby causing them to huss at it.
"Oh look! There's some cats up there." The voice of their friend Mary accompanied her pointing at them.
"Where?!" Marlene whirled around in a circle before her girlfriend, Dorcas, took her head and gently directed her gaze in the direction of where they were.
"Awwww!"
Afyer exchanging a glance, the three felines jumped off the wall and made a run for it.
Once they were in the clear they transformed, all it took was one look at each other before they burst out laughing, they only stopped because they couldn't breathe.
Later when everyone was sitting in the common room sofas talking among themselves, Mary cleared her throat to get their attention.
"We saw something today." She fidgeted with her bracelets.
"Ooh yeah! We saw three cats outside, my favourite was the black one- it was so small and cute!" Marlene cut in enthusiastically.
Remus snorted and elbowed Regulus, earning himself a death glare.
"Mine was the big brown one, it looked really fluffy." Dorcas said into Marlene's hair, just loud enough for everyone to hear.
An elbow into Remus' side, courtesy of Lily.
"I liked the ginger one, in fact it was the exact same shade as your hair Lily."
An elbow into Lily's side, courtesy of Regulus.
"Aw no way, I want to see the cats." Sirius whined.
"Me too." James leant against the back of the sofa with a wistful sigh.
"I'll pass thanks." Peter looked slightly green.
The other three marauders burst out laughing at the irony of Peter being scared of cats.
3.
Having finished all of his homework and had his fill of revising, Remus took full advantage of his cat form by spreading himself across the laps of his two friends.
"Really Rem?" Lily chided even as her hand stroked his fur.
"You're like a heated blanket." Reg smiled down at him before continuing writing his potions essay.
Two pairs of footsteps approached their table, which was odd as they had chosen an isolated one for a reason.
"Hey guys?" Peter sounded wary.
Sighing, Lily put down her quill and faced them, thankful that the table was blocking their view of Remus, "What?"
"Have you seen Moony? We can't find him anywhere, and he's put the map somewhere." Sirius sounded slightly more confident.
Reg also sighed and put his quill down, "He just left to go to your dorm I think, now go away we actually have things to do."
Both boys brightened at that, turning and running out of the library with a "Thanks guys!" Thrown over their shoulders.
"Well then Remus, they're looking for you."
With the cat equivalent of a groan he rolled off of them and changed back.
Grabbing his bag and slinging it over his shoulder he ruffled their hair as he walked past, "See you guys later."
4.
It was only Lily and Remus that evening, Reg had agreed to meet them later as he was spending time with his friends in his own year.
The two of them were laying in an alcove in the corridor, enjoying the cool stone and the quiet.
"Psst James, Pete, it's those cats Mary said about." Sirius was standing a few metres away with James and Peter, two looking curious while Peter looked quite nauseous.
"Be careful guys, you don't know if they're friendly."
James snorted, "Who would've thought a rat would be scared of cats."
"Hey!" Peter shoved him lightly with a smile.
"Come on, let's find out." Sirius inched forward, crouched down on his knees and started trying to attract the two in the alcove.
James joined him a second later, making kissy noises and rubbing his fingers together.
Both cats blinked at them, amused but unmoving.
"What are you doing?" Regulus sounded extremely confused as he walked towards them.
"Shhhh! The cats Mary was talking about are here."
Regulus raised an eyebrow at his brother's antics before peering into the alcove and stifling a snort.
"Oh it's just my friends cats, I'll take them back to her." He made a clicking noise and walked in the direction of the Slytherin common room, the two cats instantly stood up and followed him away.
"What the-"
5.
Deciding to spend the evening on the big sofa in the common room was an easy decision.
The three of them had yet again formed a cuddle pile and were dozing off peacefully.
When they were sure that the three cats were asleep James and Sirius put their plan to action, scooping up the cats and carrying them up into their dorm room.
Once they got there they wedged the door open and placed the cats on Sirius' bed.
As they thought they should wait for the cats to wake up on their own, the two boys settled onto James' bed and passed the time by chatting.
Unbeknownst to the two boys, one cat had woken up and had set about waking the other two so they could make their escape out of the open door.
Lily nudged Reg awake and moved on to Remus.
Once all three were awake they darted out of the room, hearing the exclamations of their two friends, and ran down the stairs.
Checking the coast was clear- it was- all three turned back to human and started walking up the stairs as if they'd just arrived.
"You got your grade for that essay you were doing the other day yet Reg?" Remus asked as they entered the dorm.
"Yeah, lost one or two marks but overall did okay."
"Oh that's great." Lily smiled at Regulus before collapsing backwards onto Remus' bed.
"Oh!" Remus turned to Sirius and James, "We thought we saw some cats running down the stairs when we came into the common room- did you catch them or something?"
James ran a hand through his hair sheepishly, "Yeah we waited until they were asleep so we could show you guys them in our room."
"Huh, guess that didn't work." Lily chuckled.
"Yeah, but we'll get them next time to show you." Sirius said hopefully.
+1
It was the Sunday after the full moon and Remus was exhausted so he quickly agreed to spending the day in his room with his friends, his bed specifically.
This cuddle pile was the best one yet, they'd made a den of cushions, blankets and Remus' jumpers and were curled up in the middle of it sleeping the day away.
It was mid afternoon when Lily woke up, with a dry throat.
Extracting herself from the pile carefully she jumped to the floor and turned back into her human form before climbing back in the bed and nudging the cats awake.
"Do you guys want anything? I'm thirsty so I'm going to go down to the kitchens."
Regulus hopped up onto a cushion and stretched out with a yawn, after he was done he nodded and sat down to wait for her to guess what he wanted.
"Uh hot chocolate for you Reg?"
With a happy meow he nuzzled her hand and climbed back into the makeshift den.
"Rem I'll get you some tea because you're not going to be moving anytime soon, and I'll get some biscuits for all of us too. See you guys in a minute."
With that she walked out of the door, leaving them to their own devices.
Remus fell back asleep easily as Regulus draped himself over the other, soon also falling back asleep.
A few minutes later, Lily opened the door with her hip because she had a tray in her hands.
She set the tray on Remus' trunk and knelt on the bed, gently shaking the cats.
"I'm back, shift so you can drink something please."
Both shifted back, Remus laying flat on his back and looking like he was very much in pain, Regulus was sat next to him wiping his eyes to wake himself up properly.
Lily retrieved the tray and joined them on the bed, handing Reg his drink and helping Remus to sit up so she could hand him his too.
"You're both angels, my mam would love you both." Remus said just before he took a gulp of his tea.
They got halfway through the packet of biscuits on the tray before Lily decided they'd all better stop, so she collected everything and put it on the tray again.
Slipping off the bed she looked around the room, and froze.
All 3 of the other residents of the dorm were sat on Sirius' bed, gaping at them.
"How long have you been here?" Lily asked as she set the tray back on Remus' trunk.
"Uh only the whole time?" James jumped off the bed to steal a biscuit.
"Are you guys animagi?" Sirius caught the biscuits thrown their way, handing one to Peter.
"Huh, didn't notice. Yeah, yeah we are animagus." Lily say back down on the bed with a sigh, realising they'd have to register now.
"Wait can we join your cuddle piles then guys?" James exclaimed excitedly.
"I guess, but you're humans." Regulus answered.
"Just show them guys, then we cam sleep again." Remus covered his eyes with his arm.
"Me first!" Sirius bounced off of his bed and landed on all fours.
"You're a dog?" Regulus laughed.
His only answer was a bark.
"My turn then." Peter stepped forward and morphed into a rat.
"Ohhh that's what you meant about rats being scared of cats the other day." Lily realised.
"Yeah, we learnt last year to be able to help Remus on the full moons, oo you guys can join us next one!" James grinned.
"Your turn James." Lily gestured impatiently for him to show them.
"As you wish." He bowed and turned into a stag.
"Oh prongs, I get it now." Regulus started laughing again, setting the rest of them off.
They moved the den onto the floor and added more blankets and pillows so there was more room for all of them.