A/N: Had this idea for a long while; finally bulldozed and wrote over 3/4 of it tonight lol.
"Okay, so what are we doing?" Stacy asked after Candace dragged her to the living room, where Perry looked like he was trying to take a nap. He must have been tired after his mission. It was sort of hard to reconcile that this adorable napping creature was a butt-kicking sentient secret agent.
Candace whipped out a camera. "Okay, so Jeremy was telling me about this prank thing his family decided to pull on their poodle. Then he told me that he'd like to see how Perry reacts to me playing dead and how I should record it, and I was so distracted by how cute he looked that I just said yes. But I can't record it and play dead at the same time, and if I ask Phineas and Ferb to record it for me, they'll make it some ridiculously bust-worthy thing, and Jeremy said I had to be the one to play dead–"
"So you want me to record you playing dead in front of Perry," Stacy summarized, "to see how he reacts to it so you can show it to Jeremy."
"Yeah."
"Okay…I guess I can do that."
Candace handed the camera to Stacy, continuing to explain, "And I think you should try to hide so Perry doesn't feel like being lazy and not checking on me just because he sees you right there."
"Ummm, okay, I'll hide behind the couch," Stacy climbed over it and set up with the camera. "I guess my lack of reaction would give it away, yeah."
"Exactly!" Candace agreed. "Okay, now record!"
As soon as Stacy was ready to record, Candace impressively flopped over onto the floor, lying spread-eagled not entirely comfortably.
Perry chirped a little from the disturbance and blearily opened his eyes to examine. Once he saw the noise had just been Candace and that she couldn't see him, he rolled his eyes slightly at Stacy and then closed them again, settling deeper into the bed.
Stacy burst out laughing at his indifference of Candace's antics.
"Stacy!" Candace whispered harshly from her position on the floor. "You're not supposed to laugh!"
"Sorry," Stacy tried stifling her giggles, "but he just closed his eyes again to go back to sleep."
"What?" Candace jumped up. "Seriously?"
Sure enough, she saw that Perry had been trying to go back to sleep. Stacy could tell from the tension in his body that he wasn't quite asleep, but likely just pretending to be at the moment.
"Perry!" Candace scolded, reaching over to grab him, which fully woke him up. In retaliation, Perry growled and snapped his bill at her, clearly displeased at being taken from his nice comfy bed. They all knew he would never bite her though, so the threat was not nearly as effective as he likely had hoped.
As he changed tactics and started squirming instead, Candace complained, "Oh, c'mon, you little meatbrick! I'll get you some treats, and then all you have to do is react in some way to me faking my death and then you can get back to your nap!"
Perry visibly resigned himself to his fate and flopped in her arms. They disappeared from Stacy's view into the kitchen, and when they returned laden with snacks he looked only marginally less annoyed.
Candace uncharacteristically gently set Perry on the floor and then opened up one of the bags. She held one of the treats for him, which he swiftly snapped up in his bill. After he finished that one, she then placed a few more on the floor.
"Okay, let's try this again," Candace said before purposely falling to the ground again, a safe distance away from where Perry was munching.
This time at first seemed to be a failure as well since he just kept on munching. After he was finished with his snacks, however, he turned back to Candace. Slowly, Perry creeped forward until he was right next to her face.
Likely for some sort of revenge, Perry licked across Candace's face.
"Ew, Perry!" she bolted up, shrieking and shoving him away. "Gross! Your breath smells like platypus food!"
"It's almost like you just fed him that," Stacy deadpanned.
Candace glared at her. "Okay…that was almost a good reaction. Think you can get it this time, meatbrick?"
Perry stared wall-eyed impassively at her.
"I'm taking that as a yes." Candace, once again, fell dramatically down to the floor. Perry continued staring at her, until he apparently decided enough was enough and just up and left the room.
Stacy was about to comment on his absence when Mrs. Flynn-Fletcher walked into the room, asking, "Candace, dare I ask what you are doing?"
Candace groaned from the ground, "You just ruined it, Mom."
"Well, I'd say sorry for ruining it, if I knew what 'it' was," Mrs. Flynn-Fletcher said. "And why is Stacy sitting behind the couch with a camera?"
Stacy waved in response, "Hi, Mrs. Flynn!"
Just then, they could all hear Phineas and Ferb running down the stairs. They popped around the corner, with Perry leading them. He led them straight up to where Candace had now sat up on the floor, and then he plopped down beside her.
"What's up?" Phineas asked the whole room.
"I'm trying to play dead in front of Perry so he will give some sort of reaction that Stacy will record so that I can show it to Jeremy," Candace explained with a sigh. "But he isn't exactly cooperating."
"Well, he did come and get us," Phineas pointed out.
"The first time he just went to sleep," Candace grumbled.
"Perry's probably smart enough to know you're fine," Phineas explained. "Animals have a much better sense of smell than humans."
"You really think he's smarter than a poodle?" Candace asked.
"Yeah, I don't see any reason why not! Perry's really smart," Phineas knelt down and petted his pet. "Isn't that right, old boy?"
Perry chattered contentedly in response.
"Well, if he's so smart, can you somehow get him to react? Preferably without licking my face?"
"Sure! Ferb and I'll join you!" Phineas declared enthusiastically.
"Okay…" Candace was skeptical but didn't try to stop him.
Mrs. Flynn-Fletcher must have taken that as her cue to leave, apparently satisfied with the answer.
As Candace fell down to the floor, Phineas and Ferb joined her just as dramatically. What Stacy hadn't expected, however, was that after a few seconds of hesitation, Perry flopped over on his back next to them and sprawled out his arms in imitation. This time, Stacy managed to not break out laughing.
Phineas peeked an eye open and then started giggling, "Perry, you're not supposed to play dead too, silly boy!" All the kids sat up, and Phineas reached over and placed Perry right side up again, still giggling.
"Ugh," Candace said. "Why can't you just be normal, Perry?"
"If he was 'normal', he wouldn't be our Perry," Ferb declared, which had Candace begrudgingly rolling her eyes.
"Okay, but we're only trying this once again. After that, I'm done." Candace flopped to the floor one last time, then Ferb, and then Phineas quelled his giggles just in time to join her and Ferb.
Stacy could swear she saw the gears turning in Perry's head as he sat and ruminated on the next course of action. She knew he was smart enough that he knew exactly what was going on and what kind of reaction Candace wanted, so he was purposefully choosing not to give it to her. What Stacy couldn't decipher was whether he had some other idea or if he was just doing it out of pettiness. With the boys here, Stacy was leaning towards the former.
Eventually, Perry waddled up to in between Candace and Ferb and spread out his paws, touching both of them on the chest. He then started flexing his little fingers, which made Candace yelp and Ferb jump.
"Perry!" Candace giggled. "Stop tickling me!"
Perry did not, in fact, stop tickling her or Ferb. They tried tickling him in retaliation, but he was really only ticklish at his involuntary reflex. Phineas leaped up and joined in, trying to tickle Perry to get him off of them, only for Perry to use one of his other paws to tickle him as well.
In a matter of seconds, they were all in a giggling heap of tickles on the floor.
"Okay, okay, that's enough!" Candace exclaimed, but at least she had a happy tone. "Did you get that recorded, Stace?"
Stacy threw a thumbs-up above the couch.
"Great! Then all I have to do is show it to Jeremy!"
Candace snatched the camera from her, and then she was out of the house in an instant. As Stacy climbed out from behind the couch, Phineas and Ferb left the living room to go to the kitchen where their mom was now cooking supper. That left Stacy and Perry alone.
"Well, hopefully at least Jeremy finds it cute—wait a second, you reacted all those ways for that reason, didn't you? You knew he would get a kick out of it? Which would make Candace happy?"
Perry slowly winked at her, just enough that if you didn't know about his intelligence, you wouldn't notice it.
There was her answer.