Krang's extensive backstory in the original series is explained through episodes

[gobo]

In ep 2, Shredder says it wasn't until he came to NY that he gained his vast technical knowledge. Krang and his kind were obviously relieved of their bodies before Krang made it to Earth, unless you just want "THE FOUR MUSKETURTLES" to be a shining example of retcon. Also, I'm pretty sure Beserko only indicated they designed the 'Drome in Dimension X.

Originally Posted by JLS

Do you know which episode this was in CyberCubed? ...I'm just curious because I don't remember.

"NIGHT OF THE ROGUES" was the only TV appearance of both Antrax and Scumbug.