Do you like the idea of the membrane siblings having a mom or do you like them being clones instead?
Follow up question, do you have any lore about their mother?
I think them having a mom opens up a lot of interesting possibilities and I don’t like the clone idea specifically because it closes the door on them, among other reasons.
My favorite and most elaborate idea is that their mom, Peg, was a lot like Dib. She was over-eager about investigating an alien signal and got sucked through a wormhole to Irk thousands of years in the past. Irk was on the brink of collapse due to pollution making everyone sick and infertile. So in order to save them, Peg developed the Irken’s PAKs and their cloning technology. Peg’s first successful artificially incubated Irken was designated “Male Irken 0”, or “MI-0”, and she got the idea to name him “Zim” after seeing it reflected backwards. Peg raised Zim as if he was her own child, but always lamented that she would grow old and die thousands of years before her actual children were born, and that Zim would never get to meet them.
Peg also developed the Control Brains to help run things, but they eventually turned on her and took over Irk. Zim was killed defending her and Peg was put into stasis and hidden away.
The Control Brains tried to eradicate all knowledge of Peg's existence and present a false narrative to new generations of Irkens, but her story lives on in legends passed around by rebel Irkens living on the fringes of society. Over the years however, details have gotten fuzzy. By the present day she's believed to have been a matriarchal deity worshiped by Irken cultists as the goddess "Pig Mom Brain".
Since Irken PAKs get reused after they die, the original Zim's PAK ended up back in rotation at some point and attached to a new Irken smeet who became the present day Zim. But although the data on his PAK was supposed to be erased, traces of the original Zim's memories still exist. So Zim is eventually able to recall his past life of having been raised with a mother's love and his hatred of the Control Brains, which subconsciously influenced him to sabotage the Irken Empire his whole life.
