Why didn't Krang every...
 

Why didn't Krang every use the mutigen to mutate himself a new body?

Perhaps Krang didn't want to be a mutant himself?

Well, you can't mutate a nonexistent body. If Krang used to mutagen on himself he'd wind up as a mutated brain, if anything. :P

Maybe mutagen would have devestating results if used on brains alone.

Muated brain
 

Maybe Krang is a muated brain. Not of someone from planet Earth, but from some planet in Dimension X.

No it was shown that Krang was the head of an alien body.

By way of the original cartoon's retarded mutagen logic, I wonder what would result if a man touched some mutagen, and then touched Krang. What would result of the man, that is.

Yes, it was. In the episode, "INVASION OF THE KRANGEZOIDS", which was written by the same man who outlined Krang's backstory in the pilot season, Krang clones himself, and the clones regenerate the body Krang lost. Their heads were the same size and shape of the brain sans arm tentacles.

Likely a mix of a human and the reptilian species that Krang originally was. It's not like Krang just has "brain DNA." He's still part of that species.