What is Earth's dimension called?
 

It's kind of contradictory as to whether Dimension X is a separate universe or a galaxy (it's talked about/portrayed as both interchangeably) but is there any name for the universe dimension Earth exists in?

In 4kids they called it Dimension third-Earth during the Battle Nexus episodes.

Hmm, third-earth- sounds like thundercats.

And Usagi's home dimension was called 2nd Earth, IIRC. So we know there were at least TWO Earth dimensions- in 4Kids, anyway.

Dimension Y, stop asking stupid questions. What's next? Ar you going to ask me which dimension Dimension Z is?

I have always heard it just being called Earth. I also heard it being called Turtle Prime in Turtles Forever.

Turtle Prime? Turtle Prime was the Mirage comics' dimension, the "Prime" version of the turtles if you will.

Actually, Dimension Y is the one that Ogg was from, wasn't it? I recall Krang talking about it in that episode.

The Universe, just as Earth's Moon (natural satellite) is simply called the Moon. The term "dimension" is synonmous with universe when applied to the term "parallel dimension".

"Odyssey" assigns the various different TMNT universes different dimensional letters. Not that it'll ever be followed for anything official.

I made a thread years ago about Dimension X being a galaxy or a Dimension.

I think I liked the idea of Dimension X being both a dimension AND a Galaxy. My theory dealt with the Archie Universe being Dimension X, since we see it was possible with just a ship to travel to Dimension X. I also think I had a theory that Krang went from Dimension X to the OT universe which would explain why Krang was from Dimension X, another Universe and a Galaxy but that probably has too many holes.

I also made a thread about all the Turtle Universes nearly 10 years before ago, way before Turtles Forever and the Turtle-verse being a popular discussion in the fandom.