You fall asleep then suddenly you wake up to big splashing sound that startled you. "What the..." You began to think but you suddenly spot a man floating near the top of your swimming tank. You bounded up and swam towards him to investigate,"Is there an opening somewhere? How did he get in? How will he get out?" You thought charging for the ceiling above him.
You rammed the ceiling and it budged slightly as if there was a metal door locked shut. Despite your best effort you only managed to bash your head against a metal object which went as well as any normal person punching a brick wall. "Ah fuck!" You roared grasping your skull, but then you saw the man struggling around trying to swim away from you.
It was then it hit you, there wasn’t much air at all if any in this aquatic prison of yours. The man was surely going to drown if you didn’t do something fast, and you weren’t sure what to do. You panicked just as much as he was right now, but suddenly you felt something inside of your body call out to you.
At first you thought your ravenous craving for blood and meat was back, but you could tell that somehow this was different. Somehow you think you could do something that would benefit both you and him equally, as well as save his life.
Thinking fast you dashed after the man, and you trusted your own instincts more than anything else right now. You rushed towards the man swimming as fast as you could then you bit him and dragged his body down to the bottom of the tank.
You released him then paused as you saw his blood seeping out of his wounds, and his eyes slowly shut. "Oh fuck! What have I done?!" You thought at first but then suddenly his eyes snapped open, and his wounds started slowly closing. Moments later flaps formed on his neck that looked similar to yours, he had gills now.
"Holy shit! It actually worked!" You shouted then suddenly black scales started forming across his chest and you paused then asked,"Well shit, what have I done?"
Suddenly the man turned to you and yelled,"What the hell?! Why the fuck are you talking?!"
"Talk....wait you can understand me?!" You yapped shocked and the man noticed his hands starting to change and he screamed,"Ah! What the hell is happening?!"
You quickly rushed over to the man and he screamed and tried to swim away then you grabbed his shirt and said,"Wait, I won’t hurt you again, just please listen to me. I’m not some kind of monster or anything!"
"You tore into my back and chest with your teeth!" The man yelled and you roared,"Because I was acting on instinct and trying to save you! There’s no air in here, so I had to do something before you drowned and died."
"Wait, you tried to save me?" The man asked then his body started shifting and his bones were all cracking. He screamed as this happened then you paused and said,"Yes, but...I think you’re becoming like me...I think?"
"You think? Wait I'm gonna be a giant whale beast thing?!" The man asked and you paused and thought,"Is that how big I am?"
You shook your head to focus and you swam up to the man and said,"I think, I mean I'm not really sure what I am but....at least you’re alive. You’re just gonna have to hold out, alright?"
The man’s hands and feet soon turned to large webbed claws like yours and fins began forming on his back and underside. "ThIs hURt's sOooO, Much!" The man yelled as his voice started fluctuating and cracking with his body size before it finally became deep as his face stretched out with his skull into a muzzle.
"I know, but trust me when I say that it’s only once." You then took his claws and growled,"Just hold on!" The man’s clothes were already in tatters, and you watched his tail sprout out of his rear and his dorsal fin extend down to that.
"Oh god! What’s happening to ack!" The man growled as horns stabbed their way out of his skull, and his eyes, and mouth all changed to match your features. The scales had almost completely covered the man now, and his body bulked up with his massive size increase, and he was slightly bigger than you overall.
"It’s okay, the worst part's over." You said looking the new leviathan in the eyes then suddenly he blushed and growled,"Oh fuck, why now?!"
"What is it?" You asked then he shoved you away and growled,"Look away!"
You were confused as to why he said this then you noticed a scaled set of balls form next to a sheath around the man’s dick. Then you watched as his cock split into two penises and each grew to extreme proportions. At your size his cocks were roughly 10 inches, but you were far larger than any human so it was more like 10 yards.
It was then the leviathan roared and grabbed both of his dicks and began jerking off madly and you watched him and covered your mouth while slowly reaching down to your pussy. "Holy fuck, he’s so big, so...powerful so......masculine..." You muttered then paused and looked down to see that you had penetrated yourself with one of your claws and blushed.
The leviathan then roared as loud as he could and you saw his seed spew out all over the tank, and you even took cover and blushed as about one-ninth of the tank was now soiled with cum and you covered your mouth shocked.
The leviathan then turned around and saw your face and blushed himself, his transformation was complete and now he was just an extremely attractive male in the same tank as you. "I....I.....you...." The leviathan began but like you he was at a loss for words.