Fifi is walking down the street, still in her kitty form & sporting a red sparkling dress with matching high-heel shoes, going down the sidewalk to the beat of "I'm Coming Out" by Diana Ross.
As she's walking along the sidewalk, several different alleycats all peeked out from different locations & spotted Fifi, going head over heels for her, wolf whistling, hearts beating out around them, all that stuff. Another random cat was stepping out of a pet store & spotted Fifi, his eyes popping out of his sockets & turning into beating hearts. Fifi giggled as she strutted right by him & brushed her tail under his chin, which caused the kitty to melt into a heart-shaped puddle. A random man then stepped out of the same pet store & slipped on the melted cat.
Fifi continued walking down the sidewalk until she reached Furrball, who's all clad in a fancy black tuxedo.
"Bonjour, mon cherie", Furrball greeted as he held a hand out to his girlfriend.
"Bonjour", Fifi responded, taking Furrball's paw. Furrball then pulled Fifi forward & spun her into his arms, which made Fifi exclaim in surprise & giggle as she rested in her lover's arms, looking up into his smiling face.
"Fifi?", Furrball started.
"Yes, my love?"
"Wake up."
"Huh?"
"Wake up!"
"What are vous-"
"Fifi! Wake up!"
Suddenly, Fifi felt herself being tugged sideways, as if someone's pushing her. She closed her eyes & opened them back up. She's now in bed in her Cadillac home, with Furrball pushing on her shoulder.
"Get up, Fifi! We're late for school!"
"We're what?!", Fifi jumped up out of bed in shock. Wasting no time, the two cats grabbed their school supplies & bolted out the door.

The front doors of Acme Loo opened up, as Furrball & Fifi both stormed in & sped down the hall like a couple of dragster cars in a race.
However, their trip to class was cut short as Gogo, dressed as a police officer, stepped in front of the two felines & shouted in a gruffy voice, "HALT!", stopping them dead in their tracks. "Do you two have a pass?"
"No, we just got here", Furrball answered.
"You know you're both 12 minutes late, right?"
"Yeah, but-"
"TARDY!", Gogo screamed as he took out a couple of large stamps & planted them onto Furrball & Fifi's forehead, both marked with the word 'TARDY' in big red letters.
"Now be a couple of good students & make your way to class", Gogo instructed the couple as they both started walking casually to their destination. "Have a nice day", Gogo waved to them before he walked off to continue his duty as hall monitor.
Once Furrball reached his classroom with Fifi, he opened the door & heard the sound of Cliff's voice speaking.
"...like clams, scallops...", Cliff said, writing on the chalkboard before he & the rest of the class turned to the two kitties entering the room. "Oh, hey! I was wondering if you'd show up at all."
Furrball & Fifi opened their eyes in surprise as they looked & saw that there are a few things that notably changed. On the teacher's desk were a few different jars & containers, each housing different aquatic specimens such as octopus, fish, and other marine creatures. The chalkboard had several different words written in capital letters, which were PORIFERA, CNIDARIA, MOLLUSCA, ARTHROPODA, ECHINODERMATA, and CHORDATA. The word 'sponges' was written under PORIFERA, while 'jellyfish', 'anemones', and 'corals' were listed under CNIDARIA, and MOLLUSCA had 'clams' & 'scallops' written under it by Cliff, just as Furrball & Fifi stepped inside. The rest of the bolded words were blank underneath.
"Cliff?", Furrball asked. "What's going on here? Where's Sylvester?"
"He's unable to teach today", answered the tan cat. "Claimed to be involved in a 'freak bird-hunting accident'."
Right outside the nurse's office, Sylvester is sitting on a chair with various bandages, an arm & a foot in a cast, his other arm bent backwards, his tail twisted & sprained, and his head inside a bird cage.
"I hate my life", he complained.
Back at the classroom, Cliff said, "So I decided to step in & be today's substitute teacher."
"How is that possible?", questioned Furrball.
"Well, I offered Bugs to step in & teach you guys a very interesting subject. Something that I have a great passion for, as much as music."
"What are vous teaching?", Fifi wondered.
"Marine biology", Cliff responded.
"Ooh!", Fifi squealed. "Zat eez a tres fantastique topic, no?"
"It sure is. So, why don't you two have a seat? But first...", he pulled out a little rag & wiped the word 'TARDY' off Furrball & Fifi's foreheads. "That's better."
"Thanks, buddy", Furrball said as they both sat down at their desk while Cliff continued his lecture.
"Now", Cliff said, "as I was saying, clams, scallops, abalones, and chitons are all different types of mollusks. What makes them all fall under the mollusca category is that they all have one single muscular foot for mobility, much like snails & slugs."
"Does Hamton also fall under that category?", asked Plucky. "Because he only has one muscular foot from being lazy."
"Hey!", Hamton scolded the green mallard.
"Okay, let's hold our tongues on the insults please", Cliff told Plucky. "If you want to insult anyone, insult Monty."
"Why me?!", Monty exclaimed.
"Anyway, like I was saying, all these mollusks have a single muscular foot for mobility, and they also have what's called a radula."
"What's that?", Heather wondered.
"The radula is the tongue of a mollusk, which is covered with layers of tiny, microscopic barbs."
"Oh, so it's similar to my tongue?", questioned Furrball.
"Not quite. Your tongue, and mine too, are more like brushes. A radula works more like a saw; it's made to cut up their food & scoop them up. I have a little sample right here...", he went to the desk & took a small glass capsule, which has a tiny stick-like object inside.
"If you look in through this side, you can see all the teeth along the radula here." He pointed at one side of the capsule, which works like a magnifying glass, and handed it to Buster. "Go ahead & pass that around so everyone can have a chance to see for themselves."
Once Buster peeked through the glass & saw the teeth on the radula, he handed the capsule to Babs as Shirley held up her hand for a question.
"Yeah?", Cliff said, pointing to Shirley.
"Like, do you have your own favorite mollusk or some junk?"
"I sure do & I'm so glad you asked, because I have a heck of a story to tell you."
"Ooh! Do tell", Calamity added.
"I will. One day, my mom & I were up at the Fitzgerald Marine Reserve in Moss Beach, doing some tidepooling. At one point, I came across a large dark red object, and I thought it was some kind of rock at first. But we took a closer look & saw that it was, in fact, a giant gumboot chiton."
"Ooh! How big was it?", spoke Hamton.
"Well, just to give you a size comparison..."
Cliff reached into a bucket sitting on the desk & took out a small grey circular object & held it out toward the class in the palm of his hand.
"This right here is a regular chiton. Small, plates exposed on its back, and it got these little bristles surrounding them."
"Ah, I've seen those things before", Buster commented.
"I sometimes find bits of them on the beach", Babs added.
Cliff then took out a small bucket & reached into the water, before pulling out a large red oval-shaped blob-like creature, which is slightly bigger than Cliff's paw!
"Now THIS...", Cliff said, "is a giant gumboot chiton."
"Sacre bleu", Cosette exclaimed. "Zhat theeng eez HUGE!"
"That", Furrball pointed at the gumboot chiton, then to the other smaller chiton, "is related to THAT?!"
"Yup. It's a mollusk, large muscular foot underneath, plus it has its plate covered under its hide. In fact, if you rub the top of this chiton, you can feel the plates under its skin."
Some of the toons got out of their seats, reached out & ran their fingers along the top of the large mollusk in Cliff's hand.
"Oh wow", Buster exclaimed.
"Oh yeah, I can feel them", Babs said, feeling the lumps along the top of the large chiton.
"Like, it feels leathery", Shirley commented.
"Yeah", Cliff responded, "it has a unique feel to it, at least compared to the other chitons. Anyway, lemme put this big fella back into the pail. Go ahead & return to your seats."
Cliff put the gumboot chiton back into the bucket as everyone else returned to their desks. Cliff then returned to the chalkboard.
"So, that was the Mollusca family, now let's move on to the Arthropoda family. Now Arthropoda relates to arthropods, which are animals with multiple limbs & an exoskeleton."
"What's an exoskeleton?", asked Lil Sneezer.
"An exoskeleton is a skeleton that is on the outside of a creature's body."
"Eww!", Sneezer & Sweetie exclaimed.
"Yeah, I know, it sounds gross. But unlike our skeletons, which are inside our body, of course, and also grows with our body as we get older, the exoskeleton does not grow with age, and so when an animal start to become too big for its exoskeleton, they go through a process called molting. It's kind of like when a baby bird hatches from its egg. When an animal molts, they break out of their exoskeleton & develop a new one afterwards. Now some groups of aquatic arthropods includes crabs, lobsters, and shrimps."
Cliff turned & wrote down the three animals he just spoke on the board, right under ARTHROPODA.
"Now believe it or not, these three animals are also related to spiders & scorpions."
"What about dadgum snakes?", questioned Fowlmouth. "They also molt, don't they?"
"Yes, they do, but snakes aren't arthropods, they're reptiles. They don't have any limbs & they have an internal skeleton. No exoskeleton."
"What about centipedes & millipedes", asked Calamity.
"Yes, they are also arthropods. But there is one specific type of arthropods I'd like to focus on here, and that's crustaceans, such as the three animals I just wrote on the board. In fact, I got another live specimen to share with you & this is a very, very special animal."
"How special is it?", questioned Sweetie.
"Come forth & you shall see."
Everyone got out of their seats again & stepped up to Cliff, who pulled out another bucket full of water.
"You guys ready to see it?"
Everyone nodded, before the tan cat reached into the bucket with both hands.
"YAAAHHH!", exclaimed Cliff as he pulled out a small round black creature with multiple wriggling limbs & a long, straight tail. The toons all freaked out at the sight of the creature Cliff has pulled out.
"What the heck is that thing?!", shrieked Babs.
"This", Cliff answered, "is a horseshoe crab!"
"That's a crab?!", Plucky questioned in surprise, the animal in Cliff's paws waving its long tail around.
"It looks more like an alien", Hamton commented.
"Yes", Cliff answered, "this is a crab, this is a member of the arthropod family. However, despite its name, this is not actually a true crab."
"Then why is it called a horseshoe crab?", Furrball asked.
"Well, when you think of crabs, what's one thing that you associate them with?"
"Money?", Monty guessed. Little Beeper smacked the human toon's arm in disbelief, before he pulled out a sign that says "THEIR CLAWS!"
"That's correct", Cliff said, "crabs are notorious for their claws, especially fiddler crabs, because they're well-known for having one claw that's much larger than the other. But horseshoe crabs don't have just two claws. They have twelve!"
Cliff held the small animal out closer to the group so they could get a closer look at the underside of it.
"Yes, they have six pairs of claws; ten of those claws are on their legs, and they have one smaller pair of claws for their arms, like all crabs do."
Some of the toons looked nervously at the crab waving its tail around.
"What about that tail?", questioned Sweetie. "It's not trying to sting us, is it?"
"No, not at all. In fact, the tail is not a stinger, as many people would assume when they see these creatures, they think that their tail is venomous & that it could kill you. But that is not at all true. These things are mostly harmless. The only things on them that they can hurt you with are their claws, which don't really hurt that much, and these little spikes on their sides."
"Do they bite?", Sneezer wondered.
"No, they don't bite, they don't sting, they don't even have any incentive to attack or harm people."
"Zhis thing gives moi le creeps", Cosette said.
"Well, how about if I set it down on the table here...", Cliff set the crab down right-side up on the desk. "Don't worry, it can't go too far. Won't get a lot of traction on the desk when it got claws for feet."
"Where did you find this thing?", asked Elmyra.
"I actually got it as a gift from my cousin up in Washington. And guess what? He's also a musician like me!"
"Like, he's also a Rush fan or some junk?", asked Shirley.
"Actually, he's more of a fan of Nirvana. In fact, he's part of an all-feline Nirvana tribute band, called 'Purrvana'."
Furrball giggled & said, "That's a great name."
"Yeah, it is quite amusing. Anyway, let's not get sidetracked here. So like I previously stated, horseshoe crabs are arthropods, they are related to spiders, scorpions, and other arachnids. Plus, they have a total of ten eyes!"
"Ten?!", exclaimed some of the toons.
"Yes, ten! Two of them are these red marks on the front of their shell, or carapace; two under the shell, which are from their larval stage; and the rest are along the very top of their carapace. Also, these are very special animals because they are essentially living fossils. Yes, these creatures existed on this planet since dinosaurs walked the earth, millions of years ago."
"Whoa!", the toons all exclaimed in amazement as Cliff put the horseshoe crab back into the pail.
"Do you have any cuddly animal?", asked Elmyra.
"I do not", Cliff answered. "Marine animals are not for hugging & especially not for squeezing. In fact, try hugging a sea cucumber, I dare you."
"What's so special about an underwater pickle?", questioned Plucky.
"Well, this is where the echinoderms come in."
"Can I hug them? I wanna hug a sea cucumber!", Elmyra squealed.
"Uhh, you really shouldn't-", Calamity started, before he got interrupted by Cliff.
"Hey, Pratt? Best not tell her", Cliff said, before he whispered, "Let her figure it out the hard way."
"If I don't get to hug a sea cucumber", Elmyra began, "I'll hug these two kitties instead."
Elmyra started for Furrball & Fifi, but Furrball extracted his claws at the human toon.
"Try me, pea brain!", Furrball said to Elmyra.
"Hey, hey, hey", Cliff spoke up, "let's not get in a fight here. I'll send you guys to the principal's office if I have to."
Furrball & Elmyra both seemed to hear Cliff as the former retracted his claws.
"Thank you. Now, let's talk about the echinoderms..."

After class took place, Cliff is at his locker, getting out some of his supplies for his next class. Inside his locker door, he has some small Rush photos & a few pictures of Heather. Calamity then stepped up to the toony cat.
"Heya, Dirk", Calamity greeted to Cliff, who turned to him.
"Ah, Pratt", Cliff replied. "How'd I do with my class?"
"You did a superb job. I'm impressed with how much you know about marine biology."
"Thank you. Yeah, I just became attached to marine biology ever since I was a kitten, when I took my first steps into the Monterey Bay Aquarium. It stuck with me since then."
"I see, very interesting. Y'know, for a while, I've been having some thoughts about starting up my own class here in school, especially since you just had a class of your own."
"Even though I was substituting for Sylvester?"
"Oh, that's right. But still, I do wanna start my own class."
"Which subject do you have in mind?"
"Mathematics."
"Ah-ha. What specifically? Algebra? Calculus? Geometry? Trigonometry?"
"Actually, all of the above."
"Ooh, how fascinating."
"Would you be interested in trying out my class?"
"Absolutely! I do have the brains for math."
"How much do you know?"
"Quite a lot. I know a lot about algebra, trigonometry, and even a little bit of calculus."
"Do you know about the Pythagorean Theorem?"
"Yeah, A-squared plus B-squared equals C-squared."
Plucky happened to be walking by & overheard the conversation between Calamity & Cliff.
"I know about that as well", the green duck commented.
"Do you now?", Calamity asked.
"Yep! The sum of the square root of any two sides of an isosceles triangle is equivalent to the square root of the remaining side."
"That's actually incorrect", Cliff said.
"It is?", Plucky asked, feeling puzzled. "Isn't that what the Scarecrow said in The Wizard of Oz?"
"Yeah, but he's wrong. First off, it's not an isosceles triangle, it's a right triangle, and second, it's not just any two sides, it's specifically the two sides of the right triangle adjacent to the hypotenuse."
"The hypo-what-now?"
Cliff pulled out a white board & used a marker to draw a right triangle on it, along with some illustrations he's speaking out.
"So, this is a right triangle, okay? What makes this a right triangle is the fact that there is a 90-degree angle on the opposite side of the hypotenuse, which is this diagonal side of the triangle. The equation that we use to determine the three sides of the triangle is, as I stated moments ago, A-squared plus B-squared equals C-squared, with the shorter side being side A, the longer side as side B, and the hypotenuse as side C."
"Okay...", Plucky said, barely following along, "how does that work?"
"Well, let's say that you're given the numbers that A and B represents. For example, A is equal to 3 and B is equal to 4. What does C equal to? We don't know yet, but we can find out by replacing A and B in the equation. So we write 3-squared plus 4-squared equals C-squared, then we evaluate. 3-squared is 9, 4-squared is 16, add those together and you get 25. So C-squared is equal to 25, but we wanna get C by itself, and to do so, we square both sides, so the square root of C-squared is C, and the square root of 25 is 5. And with that, we have all three sides of the triangle. The sum of the square root of the two sides of a right triangle adjacent to the hypotenuse is equivalent to the square root of the hypotenuse, the remaining side."
"Well done, Cliff", Calamity said. "I'm impressed."
"I'm not", Plucky mumbled, "I am so confused."
"Guys!", Furrball voice is heard, before the blue cat suddenly appeared in front of Calamity & Cliff, knocking Plucky aside.
"Whoa!", the green duck exclaimed as he goes flying off to the side with a CRASH!
"Have you seen Fifi anywhere?", asked the blue kitty.
"You lost her?", questioned Cliff.
"What happened?", asked Calamity.
"She ran off chasing after Sweetie Bird", Furrball explained. "I tried chasing after her, but Elmyra got in my way & made me lose her."
"Well, not to worry", Cliff assured Furrball. "Just listen to the sound of a high-pitched shriek & you'll know they're nearby."
And at that moment, a high-pitched shriek can be heard just down the hall from where they're at.
"Speak of the devil", Cliff commented as Sweetie zoomed right by, with Fifi hot on her tail.
"Hold it, Fifi!", Furrball held a hand out to stop Fifi in her track, her body scrunched up in Furrball's paw like an accordion.
Fifi then removed herself from Furrball's hand & said, "Get out of le way, Furrball! I must catch zhe bird!"
Fifi attempted to chase after Sweetie again, but Furrball wrapped his arms around her to prevent her from doing so.
"No you don't!", Furrball told Fifi. "You really don't wanna!"
"Must get zhe bird!", Fifi muttered, trying to wriggle out of Furrball's grasp.
"No, Fifi! Birds are friends, not food!"
"I must have zhat bird! Give moi zhe bird!"
"Hey, I'd give her the bird", Cliff commented, "but the censors won't allow it."
"Cliff!", Furrball barked as Cliff & Calamity both sniggered. Furrball then held Fifi out in front of him, hands on her shoulders. "Fifi, you need to listen to me!"
"Let moi go!", Fifi blurted out. "My stomach craves zhat bird!"
"Fifi, stop!"
"I weell not stop until le bird eez mine!"
"Fifi!"
"Give moi zhe bird! All zhe birds!"
Fifi started laughing maniacally as Furrball sighed in grief.
"Snap out of it, Fifi!"
The blue can then slapped Fifi right across her face, stopping her laughter abruptly as her head went spinning. She reached up to stop her head, before she looked at Furrball blankly.
"Do zhat again", Fifi instructed Furrball, who slapped her once more without hesitation, sending her head spinning again, before she stopped it. "Merci."
"You okay?"
"Oui, I am fine now."
"Good", Furrball released Fifi as she rubbed her cheek where Furrball slapped her.
"I am sorwy, mon amore. I do not know, how you say, what came over moi."
"It happens. Sometimes, cats can go carnivorous when they see a bird or mouse or anything that make them go hungry upon sight."
"It's true", Cliff added. "I was taught to avoid those cravings by my mother when I was a kitten."
"Fifi, you need to learn to control yourself. Otherwise, you could end up being the literal punchline of every gag affiliated with cats & their prey."
"You're right", Fifi agreed. "I do need to work on zhat. I steell have much to learn about being a cat. I'll do my best to keep myself under control around small animals. Starteeng now."
Just then, Lil Sneezer showed up beside Furrball. "Hi guys, what's going on here?"
Upon hearing Sneezer, Fifi looked down at the little mouse with hungry eyes.
"Mouse!", she exclaimed before immediately grabbing Sneezer & dropping him into her mouth with a gulp. Furrball gasped as he pried Fifi's mouth open & reached down into her esophagus, Fifi gagging in response as Furrball tried reaching down into her stomach.
"Grab my paw, Sneezer!", Furrball called out.
"I can't reach", Sneezer's voice is heard echoing, "it's too high up."
Furrball then dunked his head into Fifi's throat & submerged half of his body into Fifi's gullet, his legs sticking out of her mouth as she flailed her arms, while Cliff, Calamity, and Sweetie all looked on in disgust & disbelief. Furrball then pulled himself out of Fifi's mouth, with Sneezer in his hand, both covered in saliva.
"Le gag! Le hack!", Fifi coughed.
"Are you okay, little buddy?", Furrball asked Sneezer.
"I think so", Sneezer answered. "Uh oh. Ah...AHHHHHHHHH-CHOOOOOO!"
The force of the sneeze spun Furrball around on the spot, the blue kitty spinning like a tornado, causing him to drill a hole in the floor below him & disappear into said hole. Everyone else looked down into the hole, before Furrball climbed out with Sneezer in his hand & set him down.
"I cannot believe you just did that", Cliff said, referring to Furrball's journey into Fifi's stomach. Suddenly, a pair of human arms wrapped around Fifi & in came Elmyra, squeezing Fifi against herself.
"At last, I found you!", Elmyra squealed in delight. "My cute little kitty-witty!"
"Hey, you put her down, right now!", Furrball demanded.
"Now that you are truly a kitty", Elmyra continued with Fifi struggling to break free, "I won't have to worry about you being stinky anymore."
A thought then occurred to Fifi. "Oui, eet eez true zhat you shall not worwy about my stink any longer. But I do have somezhing else vous should worwy about."
"Oh?", wondered Elmyra. "What would that be?"
Fifi held both of her arms up & extracted her claws at Elmyra.
"Razor-sharp claws", Fifi answered.
"Uh oh", Elmyra said, before Fifi proceeded to attack Elmyra viciously in a cloud of dust, shouting "Le rowr!", "Le hiss!", and "Le meow!", all while the others watched on with surprised eyes.
After a moment, Fifi emerged from the dust cloud, which settled & revealed Elmyra as a mangled mess of scratches & bruises.
"Ow...", Elmyra muttered as Fifi stood next to Furrball.
"Never again will vous hug a cat to le death!", Fifi sneered at Elmyra, as Furrball chuckled & placed an arm around the purple kitty.
"That's my girl", Furrball said with a smile, as Fifi smiled back.
"Hey!", Montana Max's voice called out as he stepped up to the mangled Elmyra. "What happened to you? Who did this?"
Elmyra weakly raised an arm & pointed at Fifi. Monty looked at Fifi with angry eyes, the purple cat looking back blankly.
Suddenly, the front doors of the school opened & a loud WHAM! is heard, as Fifi goes shooting out of the doors & lands on her rump onto the street.
"What was that for?!", Furrball yelled at Monty. "That was my girlfriend!"
"She attacked MY girlfriend!", Monty replied, before Furrball, Cliff, and Calamity approached the doorway to see Fifi standing up & sweeping herself off with her hands. Then, a truck drove down the road, heading right toward Fifi.
Furrball gasped & shouted, "Fifi, watch out!"
Fifi turned to see the truck coming toward her, and with no time to react, let alone do anything, she is struck by the vehicle, which sent her reeling down the road, as Furrball & the others looked on in horror.
When Fifi came to a stop, she became dizzy from the impact as the truck stopped right in front of her. The driver door opened, and out came a bulky man with a net, looking down at the purple feline he just ran over.
"Oh no!", Calamity said in fear.
"Run, Fifi, run!", Cliff shouted.
Fifi looked up at the man with the net & cried, "Le gasp!", but as she turned to flee, the net came down over her & scooped her up off the pavement.
"Well well well", the man said in a gruff voice, "what do we have here? A cat with no collar."
The man carried Fifi to the back of the truck, opened the barred door, and tossed Fifi in before closing the door.
"You're gonna spend a long time in the pound, little one", the man said as he locked the door, Fifi running up to the bars as the man returned to the driver's seat & shut the door.
"Non! Stop!", Fifi cried out. "I am not a kitty! I am a skunk! Furrball, HELP!"
As the engine started, Furrball bolted down the steps of the school & ran up to the back of the truck, but black smoke shot out of the exhaust pipe & into Furrball's face, just as the truck drove off. Furrball coughed & wheezed from the smoke, before he looked on at the truck driving away with Fifi held prisoner inside. Cliff & Calamity ran up to Furrball, also looking on at the disappearing truck.
"Don't worry, buddy", Cliff said to a mortified Furrball. "We'll get her back."