It was in New York City, Manhattan district, that the Turtles were fighting the Kraang after getting a tip that they were constructing some new Mutagen to use. They tracked the Kraang location and had begun fighting them instantly.
"Don't let them get away with the New Mutagen, guys!" Leo said slashing a Chassis in two.
"Right!" April said as she threw her fan at the Kraang bot who was carrying the container of mutagen.
The fan hit the Kraang bot which caused it to inadvertently throw the mutagen container into the air, causing everyone to scramble in order to try and catch it.
"I got it!" Mikey said as it bounced off his head. It then did a surprising thing… produce an injection needle as it flipped into the air and dropped needle first into April, right into her upper back.
"Ah!" April winced in pain, as the canister drained all its contents straight into her body.
"April!" Donnie said in concern, as April fell unconscious on the ground.
After finishing off the Kraang, April recovered, but wanted some time to herself. She felt weird after the injection, and needed some air, so she went topside.
"Uh…. I didn't think that mutagen would affect me that much…" April said. "I still don't feel so good." April said as she felt a bit sick, but strange.
Suddenly April then felt a strange sensation throughout her entire body. She felt her body start to shake.
"Whoa… What's happening?!" April asked.
The first thing that happened was that the mass of her entire body started to double by each second, filling her clothes very tightly. Her legs and arms stretched outward, and her body rose into the air while she was still planted on the ground.
"What the… I'm getting bigger!" April said.
The foundations of her clothes started to tear up in her repeated growth. Her sneakers went out first, exposing her stockings which were the second thing to tear completely revealing her bare legs and feet.
As she continued to grow, she started to feel tensions in her body.
"Ugh…now what?" April said cringing a bit as her body tensed.
The muscles on her entire body were tensing up, and then in a split second burst outward. Her arms and legs began to expand in every direction, building upon foundations of muscle. Her chest and stomach was also feeling the same effect, hardening and increasing in size, mass and strength.
Her shirt and shorts were now almost completely torn making it look like she was now wearing a small top and loincloth. The growing of size and muscle continued until it stopped at last.
"Whew...it stopped. I guess it only goes on according to the amount of Mutagen I took in." April said. "No time to figure out how big I am. I can't let the others see me like this. Gotta get out of here and go somewhere I won't be seen."
She managed to flee out of the city and into the woodlands. She got there faster then she thought, but nonetheless, no one would bother her.
"There we go. But wow..this is...pretty weird, and a bit cool." April said looking at herself.
She was standing at about 50 ft tall, her ponytail still intact. She took a look at her other features. She had put on a lot of muscle all over her body. Her arms had been magnified in muscle mass so much that her biceps would bulge out at the slightest bend or flex of her arm.
Her legs were now even bigger and thicker then those of Chun Li from Street Fighter. As for her chest area, she could fit a whole truck in her cleavage.
"This changes a whole lot. I don't think I should go back to the guys any time soon, they'll all freak when and if they see me all huge like this." April said. "So it's settled...I'm on my own like this." April said as she headed on her way.
April found it a bit difficult getting used to how she walked now, as every step she took shook the ground a bit.
"That mutagen really gave me a complete overhaul. I'm like an overhauled Amazon crossed with the 50 ft woman." She said to herself as she continued to walk through the woods. "I'm sure I can get used to being this size, I hope."
As she continued on, she looked at her torn attire.
"Hmm… This kind of style isn't exactly my thing. Plus, I think there's another giant teenage girl around who's already got this kind of outfit." April said. "Time to go find some new clothes or at least some materials to make some new clothes." April said as she continued on.
Not long after, she found a downed Kraang Vessel, and in it was some sort of material. April grabbed it as it started to form around her into some new clothes.
"Yikes! This is weird!" April said as it finished.
The new clothing was black with pink stripes. The fabric had turned into a top for her chest which wrapped around her bust a bit loosely, and was almost completely black if not for the pink stripes running down sideways on one side. The lower half formed into what looked like a cross between bikini bottoms and a loincloth. This left her stomach, arms, legs and feet exposed.
The bottom half of the outfit was likewise almost completely black if not for the three pink stripes running down the front which had cloth running down giving it the feel of a loincloth but covered her rear and privates to a certain degree.
"Not bad. A little on the skimpy side, I mean come on, this couldn't have formed into a simple shirt, pants and shoes?! Oh well I guess beggars can't be choosers." April said as she then exited the downed Kraang vessel.
"Alright, now let's figure out what I'm all about in this form." April said. "First off, that new mutagen made me huge like this. It's safe to say if I take in more of it, I'll get even bigger and even stronger. That means finding more and stopping the Kraang from using it. It'll be weird doing it on my own and without the guys,but I can probably do it, I mean just look at me, I'm as big as King Kong if not bigger." April said as she then headed on her way.
She stopped at a wide space to test her new form.
"Yeah, this is a good spot." April said. "So… let's see what i can do now."
She found a quarry of large rocks that were about her size.
"The first and obvious thing is that my overall size is equal to the amount of strength I have. So I wonder how strong I am while I'm like this?" April asked herself.
April then bent down and picked up one of the rocks to see how far she could throw it, she then threw it an astonishing 250 feet.
"Whoa! Very strong!" April said. "I think I'm quickly gonna get used to being like this. I mean, who doesn't like being this big and strong." April said and then went back to the rest of the rocks.
"I shouldn't waste all my energy throwing stuff. Lets see what else I can do." April said.
April then picked up another rock and then placed in a good spot, she then balled up her hand into a fist and punched the rock, not simply just breaking it but destroying it completely as it shattered into many small and tiny pieces.
"Yeah! I'm definitely better at punching things." April said.
April then picked up another rock and held it in both of her hands and then started squeezing it, the rock then crumbled from the massive force of April's squeezing, she had crushed it completely.
"Okay, thats arm strength down." April said.
She then turned her body around and looked at her legs.
"Hmmm…" April said. "Looking at the size of my legs, I bet i can do a lot more with them."
She tested out a tactic most giantesses did first in a fight with smaller forces… stomping.
April then took the remaining rocks and put them in a good spot she found, she then lifted her foot, observing how thick and buff it was, and then brought it down hard on the rocks. Not only did she smash the rocks underfoot, but the sheer impact of her bare foot in the ground caused a small tremor.
"Wow. I've got a feeling all of this stuff I can do is gonna get more powerful as I keep consuming more of that mutagen and keep growing and getting bigger." April said.
She then felt her stomach growl.
"Ooh, and seeing as how big I am right now, I think the only thing I CAN consume is the mutagen to sustain myself." April said and turned to a different direction. "So I'm on my own, practically a giga-amazon giantess, and I can only get bigger from here on out." April said grinning a bit. "You know what? I think this might not be so bad. In fact this might actually be a fun little adventure." April said as she continued on her way.