Well if you play Nightwolf's Ending, it says that he traps the spirit of the Dragon King in the Netherealm. So that is what Onaga looks like.

This is not the right forum, it should be in the Deception section.

To answer your question, he was a human at once. I think. Not sure, but I heard it somewhere before. Sindel's endings shows it's true body it says.

The MK: Deception Onaga's form is the true form, if you see the Nightwolf ending or Sindel ending, you can see that Onaga still looks the same, because Onaga transformed the Reptile's body into his own body...

How does he take on his true form when possessing Reptile? I don't understand. I thought it was just his soul mixing with the way Reptile looked. There is a head in the sarcophagus that look's like the DK's head. But I think it was a helmet. Why was the rest of his body bones and not his head? I think it was just a helmet and he was human once.

The way you see Onaga in MKD is exactly how his "true form" looks.

It says in the bonus disc that Reptile's body has been twisted to resemble exactly what Onaga's looks like.

Reptile's MKD Bonus Kard!

See?

And no, he was never, EVER, human. I never want to see that rumor brought up ever again.

Thank you ]{ombat...thank you...

at least someone finally cleared it up with facts instead of following pointless rumors.

Even if he WAS human at one point, they could quickly retcon it and make it something else. They did it with Cages death.

I mean, they said Goro died after the first MK, but they got rid of that story around MK4 and said he was just hiding after his loss.