“So what’s the big plan for today Toru?” Jiro asked the invisible girl. Toru had brought all the girls of Class 1-A to one of the fake cities on campus.

“Well my lovely girlfriends,” Toru said, referring to the polyamorous relationship between all the girls. “We are going to be transforming!”

All the girls cheered as they decently enjoyed transforming. Toru usually handled the ideas as she couldn’t participate like the other girls. “What have you got planned?” Ochako asked.

“Well, my outfit is sort of a hint but it kinda doesn’t make sense. You’re gonna be dinosaurs!” Toru announced in her cowboy-like outfit. “I’m your wrangler!”

“Ooo! Are we all gonna be the same Dino? Are we gonna be a pack? Can I be the alpha?” Mina asked excitedly.

“No, you’re all different dinos! I tried to match you guys to a dinosaur but I did have to take some liberties.” Toru said, loading a dart gun with a transformation serum.

Mina began to pout, “I wanna be a pack leader.”

Momo patted the pink girl on the back. “We can go to a transformation park and let you be an alpha later, for now, though we get to be cool dinosaurs.”

“Yeah but…” Mina began to say before a dart suddenly flew through the air and hit her. “Did you just hit me with a blow dart!?” Mina shouted.

“Yeah, I thought it would be a fun way to change! Besides, you don’t like serums with needles so this is a win-win!” Toru shouted as Mina pulled out her dart.

Mina struggled to get her clothes off as she began to change. She managed to get all her clothes off just in time as numerous popping noises came from Mina’s body. Her skeletal frame began to shift, her arms and legs bending and slowly lowering her onto all fours. Her neck shifted so that Mina could face forward naturally as the changes continued. Her tailbone began to extend, pushing out into a large tail that she slowly began to move around as she gained feeling in the new limb.

Her feet began to morph into rounded stumps reminiscent of an elephant as her legs bulked up to support her incoming weight. Her thighs and rear end bulked up along with her tail, her waist flaring out as her stomach began to droop down with body fat. Her arms got slightly longer and larger to match her hind legs, her modest chest shrinking away as scales crawled up her body. The only thing left to change was Mina’s face.

Mina’s horns began to grow in size, straighten out, and grow thicker while retaining their usual yellow hue. Next, the back of her head began to flare out forming a large crown. The final push came when her head swelled in size, her face pushing out as a third horn grew out near her mouth that formed into a beak. Mina let out a roar as she finished changing into a triceratops. Mina took a slow, cautious step, getting faster and more confident as a small amount of instincts filled her head to help her with her new body.

Everyone ooh and awed as Mina trotted around, showing off her new form. Momo however looked a little confused. “Are her horns supposed to be yellow? Is she supposed to still be pink? This isn’t what a real triceratops would be like.”

“True, that’s because it was based on that Dinosaur Park movie rather than real dinosaurs, plus I put in some details to help tell who’s who,” Toru explained while loading another shot.

“Well, I was hoping for a more realistic interpretation of…” Momo started saying before she noticed a dart in her arm. “Yeah, I kinda deserved that.”

Momo’s body began to pop like Mina’s putting her on all fours as well. Her changes started in her arms unlike Mina’s. Her hands flattened out like Mina’s, her arms getting thicker as well. Some key differences started showing when her front legs kept getting taller and taller, quickly dwarfing the other girls and Mina. Momo’s massive chest began to flatten away as a loud pop came from Momo’s neck, causing her head to jump up. “What was that! I thought my skeleton was done changing?” Momo said before another pop sounded off.

Tsuyu looked up at Momo and noticed something weird. “Momo, is your neck getting longer?” She asked.

Momo tried to crane said neck but ended up speeding up the process. Her head shot up to the clouds as an orchestra of pops cut through the air. Momo’s neck finally came to a stop at nearly a whopping twenty feet in length. “Woah! Oh, I’m up so high!” Momo panicked slightly, starting to wobble as her body wasn’t fully balanced.

The rest of Momo’s body began to catch up with her neck. Her body drooped like Mina’s did as more weight came in to stabilize her body, her back bulging and rising as well. Her legs quickly morphed into hind legs as a long tail formed behind her. Her tail was also different from Mina’s, it was thinner at the end and Momo felt like she had a lot of control over it. She was quickly drawn away from her tail when small spikes began to trail up her body, going from her tail to the top of her head while coating the rest of her body in red scales. The final push came as Momo’s hair fell out, her face pushing out into a snout, making her a Diplodocus. Momo’s uneasiness about how high up she was faded as her instincts started to kick in. They told her how to navigate and cool things like how she could whip her tail around and other stuff. She decided to show up by slowly standing up on her hind legs, impressively holding her balance.

“Wow! She’s so far up there! I wonder what it’s like up…” Ochako began to say before she felt a prick in her arm. She slowly turned to face the invisible girl holding the dart that pierced her arm.

“What? I didn’t wanna waste a shot.” Toru explained.

Ochako stepped back as the serum worked through her body, starting her transformation. She was surprised to find her body getting thinner, melting away all the muscle and fat on her body. Ochako looked at her arms, surprised to see them getting longer. Ochako’s hand reached what seemed to be a mid point, as her pinky and ring finger merged into one and kept stretching, while her remaining digits became small claws. Once her arms reached a wingspan that was close to three and a half feet, a thin layer of skin began to stretch out from her torso, crawling down the length of her arms. Ochako did a little spin to show off her wings to everyone while her legs were still normal. “These are actually really cool! I can’t wait to be able to fly… and actually control it.” She joked.

Ochako’s next change came around when her legs started shrinking slightly. Her feet melted into a three-toed shape as a small tail formed on her behind, a small layer of skin like the ones on her arms linking her legs together. Her torso grew even thinner as Ochako’s rib cage became more pronounced. Like her tall friend, Ochako’s neck also began to pop and extend, though it wasn’t as long as Momo’s. As Ochako’s face started to change, her head kept growing larger and larger. Her lips and nose began to push out, a large bridge forming in between her eyes and changing her field of view to favor the left and right sides of her body. Her mouth and nose melded together, hardening into a beak that continued to grow. Her beak started filling with rows upon rows of razor-sharp teeth. Uraraka’s changes into a pterodactyl drew to a close as she let out a loud screech. Like her friends, instincts formed in Uraraka’s head, telling her how to move and fly.

Jiro, Toru, and Tsu watched as she folded in her wings slightly while putting her hands on the ground, walking on all fours. She made her way onto an open street where she raised her arms and started flapping, sending gusts of wind down the street. She soon lifted off and began flying around Momo’s head, who was watching with interest.

“So, who’s next to devolve back into a dinosaur? Kero.” Tsuyu asked, turning to Toru.

“You’re next! I wanna save Jiro for last!” Toru said, aiming again.

Tsuyu embraced the dart flying towards her, letting it pierce her back before shaking it off. Tsuyu’s skeletal structure didn’t need much changing. All she did was bend over slightly more. Her tailbone started growing into a tail, getting longer and whipping around. “I never thought I’d have one of these again.” She said, quickly grasping the feeling of having a tail. Tsuyu shifted her legs, taking on a wider stance as her toes morphed into three digits, razor-sharp claws tipping the ends. Her arms shifted slightly as a digit disappeared from her hands, her nails extending and sharpening just like her toes. Her chest sank inwards as Tsuyu grew in size, her neck extending just like the others. Her hair fell out as her face pushed forward, green scales coating her body as her eyes shifted to the side of her head. Her teeth sharpened to a point as Tsuyu became a velociraptor. Tsuyu started receiving instincts as well when she started feeling a little odd.

Toru and Jiro watched as Tsuyu began to change again. Her eye started to protrude slightly, her legs grew slightly larger as webbing linked her toes together. Her dry skin suddenly became moist as Tsuyu shot her tongue out, still like her original tongue. Tsuyu jumped, surprising the remaining humans, getting a lot more height than she should have.

“Toru, what was that!?” Jiro shouted, panicking at the sight of a velociraptor running and jumping on top of roofs.

“Actually, I kinda expected this to happen. Since Tsuyu’s quirk is a mutation quirk, her quirk mutated the serum a little bit. The dinosaurs in that movie were made by splicing frog DNA so I’m guessing that Tsu’s frogginess brought out the dino’s frog attributes.” Toru explained.

Jiro stared at her for a second before sighing. “I can’t believe that made sense,” she said while facepalming. “Alright, let’s get this over with. Shoot me.” Jiro said, spreading her arms wide open. Toru nodded and shot her last dart.

Jiro felt a rush of power surging through her, her heart beating fast and hard. Jiro started to grow as her skeleton shifted her stance. Her legs slightly up her torso while her arms shifted slightly to the front, her whole frame losing its human shape to fit that of an animal. Her tailbone grew into an impressive tail that grew nearly as thick as her body was getting, her feet shifting to three digits with foot-long talons.  Jiro began to reach the height of some of the smaller buildings around her, slowly growing past them with no signs of stopping. “Alright, I can get into this,” Jiro said with a large toothy smile, which was sharpening as she grew.

Her small chest began to push out as a large rib cage filled her body. Her human arms began to shrink in size, her hands becoming a measly two digits tipped with claws. Her body rounded out as her neck extended slightly, deep purple scales coating what had already changed. Jiro finally stopped growing in size at an impressive forty feet tall, absolutely sure of what she was. “Man, I really gotta pay back Toru for making me a T-Rex!” She shouted, feeling her hair fall out around her. Her face began to grow, and grow, and grow as her eyes pushed to the sides of her head. Rows of teeth filled her expanding maw as the last traces of being human disappeared from Jiro. She let out a mighty roar, proud to be a T-Rex.

Jiro began stomping through the fake city, catching her reflection in some of the glass-lined buildings. Uraraka flew after her along with the others slowly following. “I’m glad they're having fun.” Toru mused to herself as she turned around… to face Mr.Aizawa and Principle Nezu. “Oh… hi Mr.Aizawa.”

“Hagakure, the battlegrounds are for serious training only. Not for fooling around in. Mind explaining how this is the ‘situational training’ you put on the reservation paper?” Aizawa asked coldly.

“It… is… training on how to… handle being transformed by a quirk and not freaking out?” Toru said, trying her best to cobble together an excuse.

The teacher and principal duo said nothing for a moment before Nezu spoke up. “Technically she’s not wrong. I’ll give it a pass, besides they deserve a little time to goof off. Also, it’s not like we can change them back right now.”

Aizawa groaned before slumping his shoulders. “Alright then, just lock up when you’re done.” He said, turning to leave.

Toru let out a sigh of relief as she turned to her girlfriends. “Alright! Let’s have some fun!” She shouted while climbing onto Jiro’s back. The group began to trudge through the city, making as much noise as they pleased.