A Phineas and Ferb fanfiction. I own nothing except Doofenshmirtz as a platypus in my style. NOT DoofxPerry. Enjoy!

It was a dark, gloomy, stormy summer day in the town of Danville. It was pouring outside most of the day, but the constant thunderstorms eventually settled into small, mild showers. Phineas and Ferb couldn't do much on this rainy day, so they were up in their rooms taking to their friends online and sketching out ideas of what they would do tomorrow. Candace was in her room as well, yapping on her phone to Stacy. (but she did that every day, rainy or not.) Linda and Lawrence were lazily watching TV in the living room.

Perry was joyful on this gloomy day. He was happy because Major Monogram had informed him that his nemesis, Dr. Doofenshmirtz, wasn't up to anything today, and he finally had a day off to himself. The platypus took this time he had off to get some well needed rest, since he had been putting in a lot of extra hours to fight Doofenshmirtz lately. He got himself snuggled up in his warm little fluffy platypus bed, and laid his head down to take a nap. He was just about to close his eyes and drift off too, when there was a sudden knock at the door that jolted him back awake.

Phineas and Ferb eagerly ran to answer the door, and were surprised by what they saw. There on their doorstep lied a little platypus about the same size as Perry. He had turquoise fur, just like their pet, but it was darker and a little scruffier. He also had a few strands of hair sticking out of the top of his head, like Perry had, except they were chestnut brown instead of black. The platypus looked up at them with big dark blue eyes, which had deep circles underneath them, like he hadn't slept in a while. The platypus also seemed to be slouching slightly.

Phineas picked him up and held him. "Ah, poor little guy. How'd you get abandoned out here?" he said, caressing the platypus as if it was his own pet. Ferb pointed to the ground outside their door where the platypus was found, and there was a note. Phineas read it:

"Dear who ever may read this,

I am the owner of this platypus, and I no longer wish to keep him anymore. I noticed two boys come in and out of this house and walk their platypus everyday, so I figured this family must know a thing or two about owning one. I was going to take him to the pound but I figured I should take him directly to a good home instead. Oh, the platypus's name is…uh…Doofy. Please take good care of him.

-Anonymous"

"Wow Ferb! Do you know what this means?" Phineas said gleefully. "We can give Perry another little playmate! Won't that be cute?"

Phineas held the new platypus close and gave him a big hug, which he didn't seem to like too much. Phineas walked over to Perry's bed, where the platypus was lying awake curious as to what was going on.

"Hey Perry!" Phineas said to his pet. "Someone left us another platypus! That means you're gonna have your own little playmate!"

Phineas set the dark-furred platypus down, and the two semi-aquatic mammals stared at each other. Perry thought the platypus looked almost, familiar. His chestnut-brown hair, the dark circles under his eyes, and that slouch. But the thing that struck Perry with the most curiosity was his big, wild dark blue eyes, which had just the slightest gleam of interest in Perry as he stared back.

"His name's Doofy!" Phineas said. "I'm sure you two will become the best of friends!" the red head said as he and his brother left the room.

Doofy. Perry thought. And then it hit him. Perry's eyes grew wide. But before he had a chance to react, the new platypus started talking. Well, chattering, but Perry could understand him.

"Wow! That was easier then I thought! Who knew those kids would fall for a platypus so easily. I didn't even have to whimper like a helpless animal and they still took me in as their pet!" he said in the high-pitched German accent Perry would recognize anywhere.
Perry was too shocked to respond. Why in the world was Doofenshmirtz in his house, and more importantly why the heck was he a platypus? Perry just stared, for he didn't know what to say.

"Oh, hi!" Doof greeted him. "You must be their other pet platypus, huh? Well, my name's Doofy. Didn't that kid say your name was…Perry? That is so weird, I have a nemesis named Perry, and he looks an awful lot like you!"

Perry still didn't speak.

"You don't talk much, do you?" Doof said suspiciously.

"S-sorry." Perry said, which to anyone else would have sounded like a random chirping sound, but the platypuses could understand each other. "I'm just not used to other platypuses…" Perry lied quickly.

"Well, between you and me, I'm not actually a platypus…" Doof said kind of sheepishly. "I'm an evil scientist, but I turned myself into a platypus. It was an accident, really. Allow me to explain. Earlier today, I was trying to make a machine that would make me understand platypus, so I could finally understand what my nemesis was saying. So naturally, I built it, and naturally it worked! Well, sort of. I woke up realizing that I could understand platypus, because it turned out I was a platypus! I was going to just hit the reverse switch, when it came to me that I could use this to my advantage! Instead of learning what my nemesis was saying, I could learn to live like a platypus, and hopefully find any of his potential weaknesses! And I always see you're owners walking you around Danville so I followed them home so that I could learn to be a platypus like you!"

Doof paused to laugh diabolically to himself. "So, what do you think?" he asked, turning back to Perry. "Pretty evil plan, huh?"

Perry didn't answer. He was still a little shocked, but at the same time very relieved that his nemesis was too stupid to realize that he was the very same Perry the Platypus that was his enemy. Perry was worried for Phineas and Ferb's safety since his worst enemy was in the same house as them, and if Doof figured out that Perry was his nemesis, there's no telling what he could do to harm his family. So Perry decided not to reveal his identity to his nemesis yet.

Perry suddenly came out of his thoughts when he realized Doof was staring at him. "You really remind me a lot of my nemesis you know…" he said, almost suspiciously.

Perry thought quick, and tried to say something that would lead Doof away from finding the truth. "So, uh, Doofy. Tell me, what's your nemesis like?" he asked nervously.

Doof suddenly looked pleased. "Oh what a great question! I'll tell you all about him! Well, he's a very strong, very sophisticated, macho secret agent. He fights me time and time again, and I find myself losing to him time and time again, since he is a lot stronger and faster than me. I'll admit, I have to give him respect for that."

Perry couldn't help smirking.

"But you know, even though he's been my nemesis for years, I feel…I feel…" he said, not really wanting to confess to what he was about to say.

Perry found himself a little curious to what his nemesis thought of him, and tried to get him to continue. "What? What do you feel?" he asked.

"I don't really want to tell you." Doof said. "It's a little embarrassing…"

"I won't tell anyone! I swear! Please tell me!" Perry pleaded.

"OK, I feel like I can't hate him. There I said it." He declared unwillingly. "It's like he's my best friend at times, and we kind of awkwardly crept by through the years with a 'frenemy' relationship, but I always secretly wanted more than that. I mean, he is kinda cute for a platypus, and he was always really nice to me. He listened to my back stories everyday, and even helped me sometimes. I kind of wish we could just forget all this enemy stuff, and just be best friends…" he said.

Perry was speechless.

"Yeah, pretty corny, huh…" Doof said, blushing and looking down at his toes in embarrassment.

A warm smile spread across Perry's face. "I don't think it's corny. I actually think it's kind of sweet the way you feel about me—erm, I mean your nemesis."

Doof sighed. "Yeah, well that's more than I can say for him. If I told my nemesis that he'd laugh in my face and think I'm a complete idiot, and a softy." He said, hanging his head.

Perry was surprised his nemesis would think about him that way. Perry would never laugh in his face, he even sort of liked the idea of them just being friends. They had been frenemies for years, haven't they? Why would dropping the enemy stuff be a bad thing? Perry looked at Doof, and almost caved. He needed to keep his identity a secret from the doctor for the safety of his owners, but he wanted his frenemy to know that he really didn't hate him either.

But then, Perry took a deep breath, and got up on his hind legs. He put on his fedora, and waited for Doof's reaction. It wasn't pretty.

"P-P-P-PERRY THE PLATYPUS?" he screamed, jumping up on his own hind legs in alarm. Suddenly, the doctor's cheeks turned bright red, and he looked completely humiliated. "Perry, why didn't you tell me it was you before I said all those embarrassing things?" he said, hiding his head in shame.

Perry smirked. He couldn't help it. He just loved seeing his nemesis so embarrassed! Perry tried to hide his snickering, and his face turned serious again. "Doof, you don't have to be embarrassed because you don't hate me! I feel the exact same way!" he admitted, cautiously putting a hand on the evil scientist's shoulder.

"Really? You really don't mind us being…friends…sometimes?" he said.

"Course not! We've been frenemies for so long, I've really come to like you too!" Perry said, smiling.

Doof sniffed back a tear. "Awww, thank you Perry the Platypus!" he said gratefully.

"OK," Perry said calmly. "Now that that's settled…CAN YOU EXPLAIN TO ME WHY THE HELL YOU'RE IN MY HOUSE?" he said, grabbing Doof by the arm and speaking right into his face.

"I already told you! It was an accident! I didn't know that you were the platypus that lived here!" Doof scolded back.

"Well, I'm going to have to ask you to leave!" Perry said. "I don't trust you around my family!"

Doof looked confused. "Wait, your family? That's what you're concerned about? I have no intentions to harm them! I'm not that evil! And do you have trouble hearing me or something? I DIDN'T EVEN KNOW YOU LIVED HERE IN THE FIRST PLACE!" he shouted.

Perry growled. "Well you can't stay here! So leave!" he said.

"Oh, come on Perry. I'm just getting used to this. I actually kind of like being a platypus. Can't I just stay here a while? Please? I won't be a bother, and I promise I won't do anything evil!" he pleaded.

Perry still glared at him, arms crossed. He raised and eyebrow. "Ugh! Fine! But you are so going to owe me one after this!" Perry said, apparently annoyed.

"Yay! Really? Oh thank you Perry! If you let me stay here for a week, I'll forget about evil for a week so you can have a lot more time off. Deal?" he bargained eagerly. Perry didn't budge.

"Oh come on! I'm giving you the bargain end of the deal here! If I'm a platypus one week, and I'm not doing anything evil the next week, that gives you two weeks off!" he said.

"Yeah, but I have to spend one of those weeks living with you!" Perry muttered.

Doof gave Perry a big, pleading stare, and Perry caved in.

"Well, alright." Perry said, shaking his hand. "As a friend, I'll let you stay here, but only for a week."

Doof smiled in return. For some reason, he liked the idea of spending a whole week living with his nemesis/best friend. Perry was actually being awful nice to let him stay.

"Dinner's ready!" called Linda from the other room. Phineas and Ferb came running down the stairs, with Candace following after. Everyone sat down at the table and started eating.

Doof and Perry got back on all fours and walked into the room. Candace took notice of the new platypus instantly. "Eww! Since when do we have two smelly stupid ugly platypuses in the house!" she said, holding her nose.

Doof glared at her. "Wow, she's real nice, huh?" he said sarcastically to Perry, who rolled his eyes in response. "Eh, you learn to live with her…" he said.

"Phineas, Ferb, where did this other platypus come from?" Linda asked her two sons.

"We found him on the doorstep outside! There was a note that said who ever left him here wanted to find him a good home. Can we keep him mom?" Phineas said enthusiastically.

"Well, it would be nice for Perry to have a little friend…" Linda said, pondering the idea of two family pets. Perry and Doofenshmirtz exchanged glances at the word 'friend'. "OK. You guys can keep him!" she said.

Perry growled a little. He was actually kind of hoping Doof wouldn't be able to stay and live with them. Phineas and Ferb shouted gleefully, and Candace rolled her eyes. "Ugh! How did I get born into this family! Their platypuses! Stupid, smelly animals that don't even have brains enough to understand that no one loves them! Why should we even consider getting another one?" she scolded. Doof and Perry simultaneously gave Candace a death glare.

"Candace, you have to admit, for an animal that doesn't do much, they are pretty cute." Phineas said.

Candace pondered that for a moment. "Well, he is cuter than Perry…" she said, looking down at Doofenshmirtz with less disgust this time.

Doof got a smug look on his face and stuck his tongue out at Perry, who growled and rolled his eyes in return.

"So what are you boys thinking of naming him?" Lawrence asked.

"Oh, he already came with a name." Phineas said. "The note said his name's Doofy!"

"Well that's a peculiar name." Lawrence said.

Then Phineas suddenly remembered something. He got up, and started rummaging through one of the cabinets. He took out another food bowl and a marker, and he scribbled 'DOOFY' on the food bowl. The red head laid it down next to Perry's food bowl and filled them both up with platypus food. Perry started eating, but Doof looked at the food suspiciously.

"Uh…what is this stuff?" Doof asked.

"Oh, don't be a big coward and just eat it!" Perry said to his reluctant nemesis.

Doof warily started eating the food, and when he realized how hungry he had gotten his began chowing down more enthusiastically.

"Wow, this is isn't half bad! What's in this platypus food anyway?" he asked.

"Bug larvae and worms." Perry announced. Doof suddenly didn't look too appetized anymore. In fact, he looked like he was going to be sick. And he was. The sickened platypus threw up all over the floor. Linda immediately scolded him and picked him up. She threw him outside in the backyard and went back to the kitchen to clean up the mess.

Perry nearly choked on his dinner laughing so hard. Doof just scowled at his nemesis through the glass door, and gave him a look that said 'I'm not laughing'.

After dinner, the kids went up to their rooms to go to bed. Perry followed the boys into their room, and was about to sleep in one of their beds as usual, but he was surprised when Phineas picked him up and placed him in his platypus bed instead of his own bed. "Here, boy. You should sleep down here with your new friend tonight." He suggested. Phineas and Ferb crawled into their beds and said goodnight, then shut off the lights and went to sleep.

Perry was a little mad that Phineas was making him sleep on the floor in his bed. He was much more used to sleeping next to one of his owners. He remembered the time he had slept in his nemesis's arms once, when he had passed out at D.E.I., and he had felt just as at ease as if he was sleeping with one of his owners. But would it be the same sleeping so close to his nemesis, now that he was a platypus? He looked at Doof, who was giving Perry an insistent glance from a few feet away.

"Look, it's awkward enough having you living with me in the same house," Perry said. "It would be even more awkward if you were to sleep in the same bed as me, too."

"But you slept in my arms before," Doof reminded him. "How is this any different?"

"Because, you're not a human anymore! It would be too…uncomfortable if we were sleeping in the same bed like this." Perry admitted.

"Perry, can't you just drop all this nemesis stuff for one day? I'm your best friend!" he begged.

"No." Perry said, and Doof could tell that was his final answer.

Perry got comfortable in his bed, and Doof tried to rest comfortably on the floor a few feet away. Doof sighed. He tossed and turned around, but just couldn't get cozy enough to fall asleep. It was kind of weird to be in his enemy's house right now, and it was even weirder since it was his first night as a platypus. Doof rested his head on his paws, and closed his eyes, desperately trying to get some shut-eye. But a sudden clap of thunder from outside startled him, and he was instantly wide awake again.

"Perry…" he whispered nervously.

Perry moaned sleepily and just turned over. "For God sakes, just go to sleep Doof…" he muttered.

Doof tried to get comfy again, but a freezing draft was making him shiver. He felt his teeth chatter, and he suddenly wanted to be in Perry's warm, fluffy bed. He whimpered loud enough for Perry to hear, which woke his annoyed nemesis up.

"Ugh! For an evil scientist you are such a crybaby!" Perry scolded him, apparently irritated. But Doof whimpered again, and Perry gave up. "Fine, you can sleep in my bed. But only if you give me my personal…"

Before Perry had a chance to finish his sentence, Doofenshmirtz zipped across the room and snuggled into Perry's bed.

"Space…" Perry finished with an aggravated sigh.

"Oh, sorry. I could go back on the floor if you want me too…" Doof said, sheepishly backing up.

"No, no! It's fine!" Perry said, not wanting to feel like he was being rude to his guest. "I don't mind, really. Goodnight, Doof." Perry said almost a little cautiously. It was still a little weird for him to get used to his nemesis being there. Nemesis. Why did he keep thinking of him like that? When there wasn't notorious schemes and epic battles between good and evil involved, they were friends. That's what being frenemies meant, sometimes they were friends and sometimes they were enemies. And this was one of those friend times. Perry recollected his thoughts, and tried to picture Doof as his best friend. He didn't want to keep having these awkward moments while Doof stayed over.

Then Perry noticed that Doof was tossing and turning again. A rumbling sound vibrated from his bill, and he seemed frustrated about it.

"Ugh, what is this weird noise I keep making!" he said, trying to muffle the sound by covering his bill with both paws.

"Relax Doof." Perry reassured him. "You're just purring."

"Well, why am I purring?" Doof asked curiously.

"I don't know! It means you're happy about something." Perry said, trying to fall back asleep.

Doof pondered what would possibly be making him happy right then, but he realized it was his nemesis. He vaguely recalled Perry purring when he was in his arms after he had passed out at D.E.I. It was a sign of affection, but did he really have affection for his nemesis of all people? The doctor realized he did, as he had admitted it himself earlier. But was it really right to love his nemesis as a friend? All the other enemies are just out to hate each other, but over the years Perry and Doof had formed a more special bond than that. They helped each other, listened to each other, and even missed each other when they were separated. Heck, if it wasn't for Doof being evil and Perry being good, they would be best friends. And they kind of already were. That was why Doof was purring, he was happy to have such a great best friend. On that joyful thought, the evil semi-aquatic scientist laid his head on his paws and closed his eyes.

"Goodnight Perry the Platypus." He whispered, but Perry was already asleep. And then he was too.