Disclaimer: I do not own 2012 tmnt or 2003 tmnt. Also I'll refer to 2k3 Don (who is in 2k12 Don's body) as Don and 2k12 Don (who is in 2k3 Don's body) as Donnie. If you're still confused let me know. Also if you want me to make versions with the other turtles, please tell me.

Summary: There have been many stories of the turtles switching minds. There's been an episode where Raph switched with a kraang. But what if a turtle of one universe woke up in their counterparts body? What would those two do now that they are in a different universe and their counterpart's body? Well here's one where 2k3 Don wakes up in 2k12 Don's body.

Don rubbed his eyes as he woke up. He layed there starring at the ceiling, waiting for himself to wake up fully. Once he did, his face contorted into confusion. That was not his ceiling. He pulled away the covers and sat up with his legs hanging off the side of the bed. He looked around the room slowly. His confusion starting to turn into panic.

"This is not my room. Where am I? And that is definitely not my voice. Ack." Don said then coughed a couple times to clear his throat. Don looked down to see if he was still himself. His eyes widen as he looked.

"Those are not my feet. Is this a strap connected to the belt? What the shell happened?" Don asked out loud. Then a loud knocking was heard.
"Donnie! Wake up and get to breakfast before you're late for training." Leo called out.
"I-I'll be right out Leo!" Don called back. He then tied on his mask and opened the door.

"Are you ok Donnie? You look kinda freaked." Leo asked as he looked over Donnie.
"And now I realize how tall I am. I must be close to six feet tall! I've never had to look down at Leo before." Don thought.

"I'm fine Leo. Really. I just... need to use the bathroom. I'll be at breakfast soon." Don said quickly.

"Alright then. You know where it is. Don't be too long." Leo said, then started to leave.

"Don't worry Leo!" Don called after him with a grin Then he ran over to the closest door.
He opened the door but it was just a bedroom.

"Judging by the style of the room, I'm guessing this is Leo's. But I have no idea what Space Heroes is. It looks like Star Trek." Don thought.
He closed the door and tried another. Still another room, this time Raphael's. He knew because Raph was still asleep in there. Soon he tried every room until he finally found the bathroom.
"Oh finally." Don said as he entered and closed the door behind him. Don stared in the mirror.

"This is not my face. Are those brown eyes? Interesting. They don't look half bad. And it seems he has diastema, a gap in his teeth. I wonder how that happened? It is possible it was part of his mutation." Don said. Then he sighed.
"This is so weird. I don't even know how this could of happened. But the best thing is to try and keep cool until I can fix this. Just try to not look suspicious. If these guys are anything like mine, they won't believe me right away. They'll be suspicious that I'm a bad guy. They wouldn't take the risk." Don admitted to himself.
Then he went to the toilet. "I should go to the bathroom. But it's so weird and feels like an invasion of privacy. Sorry other me, but you understand it's biologically necessary." Don thought.
Then he made himself drop down. He tried not to look out of common courtesy, but a scientific part of him was curious. So he peeked an eye open. Both of his eyes opened and widened as he looked.
"That is DEFINITELY not mine. It's... bigger than mine. Of course it would be, he is taller. A normal turtle's is about half of their length. With our mutations, they're about half of that. So a quarter of our height. If this counterpart of mine is almost six feet tall, then his would be in between 17 and 18 inches. It's interesting how it's pink too. But we are both shaped the same, a semi-turtle semi-human kind of shape." Don said to himself, getting a little lost in his analysis.
"Hey Nerdatello! Would you hurry it up already? Other turtles need to take a piss too you know." Raph called out as he pounded on the door.
"I'm finishing up now!" Don called out back.
He then quickly finished up and left the bathroom. Allowing Raph to go in. He headed down the hall since he could see a tv area from where he was. Once he was at the tv area, he could clearly see the kitchen. So he entered the kitchen and greeted morning to Leo and Mikey.
"Morning everyone." Don said as he got his morning coffee.
"Good morning! I made pizza omelets!" Mikey exclaimed happily with a big grin on his face.

Don was taken aback by that for a slight moment. But he brushed it off, knowing it would probably look weird if he didn't know what it was. Although it was probably a good guess to say it was an omelet with pizza ingredients. His Mikey never experimented like that.

After Raph finally got to breakfast, Splinter entered. He greeted his sons as usually. Don was a bit distracted with his thoughts at the moment. So Splinter walked over and stood right next to him. Then with a clear voice greeted Don.

"Oh morning sens-Ahhhh!" Don saying, but yelled as he was startled from Splinter's size. He put his hand on his chest as he took deep breathes.

"Did I startle you Donatello?" Splinter asked. Everyone else was staring at him.

"Well uh, yes. I had no idea you were... so close. I was thinking about, my next project. It's going to be a very complicated one. But very necessary. It's a big one but needs to be done." Don said, thinking quickly for a cover up.

In reality, the size of Splinter was more than shocking for Don. He was in no way expecting such a large and intimidating version of Splinter. Seeing the large rat almost gave him a heart attack. But after a few calming breathes, he recovered.

Most of training was pretty usual. What they did and how they learned was somewhat different. But nothing that was too surprising that Don couldn't handle. But then they had to spar with each other. It was Raph paired with Don and Leo paired with Mikey. Don was doing pretty good for himself. He took what he knows about his own Raph and applied that to this fight. It was until he accidentally pushed something on the bo staff.

Don yelped as the blade popped out of the staff. He was about to strike Raph with the staff. But his moment of shock left him vulnerable. And Raph gladly exploited it. He tackled Don and quickly pinned him. Raph grinned at Don and teased him for loosing.

"Well Donnie, looks like I win again. Good thing April and Casey weren't watching, huh?" Raph taunted.

"Yes. You win Raph. Can you let me up now?" Don replied.

Raph wasn't expecting that as a response. He was expecting Donnie to get embarrassed at the thought of April and Casey seeing him loose. Then tell Raph to shut up while he blushed. But nothing like that came from him. Raph mentally shrugged, not really caring and helped Don up.

"So, training over now? Cause I really need to get to my lab." Don then said.

"Yes Donatello. Training is over for today. You are all excused. Expect for you Donatello. I would like to speak to you for a moment." Splinter said.

Don froze as he was right about to go out the door. He quickly turned around with a nervous grin on his face. He went over to Splinter and sat on his knees.

"Yes master Splinter? What is it?" Don asked.

"Is something the matter my son? I sense that something is troubling you." Splinter asked.

"Of course Splinter would be the first one to figure me out. I could never get anything past Splinter. Oh what should I do? I need time!" Don thought in a panic.

"I'm sorry sensei if I'm not acting like I usually do. I have a lot on my mind. This new project is very important. I can't quite explain it, but it is. I hope you understand." Don said, then bowed his head at the end of his explanation.

"Alright, I understand Donatello. But remember, I am always here if you need to talk." Splinter said with a small smile on his face.