Was Irma originally meant to, in fact, be human?
 

The first time we get any hint that she's not human is in "A Chinatown Ghost Story," a mere few episodes prior to her being revealed to be Kraang Sub-Prime all along. That, and April and Irma already know each other in the first season, while the Kraang were after her. I think it could very well be a retcon.

I've held that suspicion. Probably we've already gotten the answer, but I'm not sure.

Do you mean in planning stages or that they wrote her to be human until close to the end of the season? If you mean the former I wouldn't be at all surprised if that was the case. If it's the latter then it's a bit harder to believe.

Irma is revealed to be Sub-Prime in the same season as she was introduced. Unless they wrote episodes one by one and sent in each script to be animated before starting the next one, thus making everything up as they went along (which to be fair, it quite often came across like they did), then I'm not really thinking that's the case. If they finished most scripts before sending them in (or at least had an outline to work from), then Irma would have likely been intended to turn out to be Sub-Prime long before any animators got to work.

Of course, the "make each script up as we go along" thing may very well be the case, the same exact character giving two contradictory explanations as for what the Utroms are probably isn't the result of airtight planning. Even so, is there anything that would indicate Irma is human and can't be much else in the mere six episodes she appears in before the twist?

Roosevelt High School
 

So, did the Irmabot just appear out of nowhere to Roosevelt High School and hung out with April O'Neil for years? Her schoolteacher would ask:

Who are you? Where do you live? Who are your parents?

When they're all outside playing soccer, someone accidentally crashes into Irma, feeling her metallic body.
"-That really hurt!" :)

I'm sure there is a Human Irma out there, or at least was until the Kraang killer her.

Rook pretty much confirmed there never was a human Irma.

I think poor writing/constant change of writers resulting inconsistent stories throughout the series.

That’s why Apritello plot is going nowhere, that’s why Timothy was frozen in Donnie’s lab and forgotten for all eternity (he’s an annoying character so I had to laugh), etc.

So Irma retcon to kraang? Very likely.

I meant more the later. Because, like I said, there wasn't even as much as hint that she wasn't human until close to the Season 2 finale. Also, while she was properly introduced in Season 2, we see her picture on April's phone in Season 1. If nothing else, I can be sure she was planned to be human back then.