Shadowbugs: Speculation (Worldbuilding, etc)
The abilities, psychology, and biology of these creatures are well-documented from years of research and observation.
However, there's one thing that nobody has figured out: What exactly happened to make Shadowbugs...shadowy?
From hidden records on Irk, it is confirmed that the populations of all Shadowbug subspecies were hit by a space-time anomaly as they were being exiled from Irk and on their way to other planets such as Earth. They passed through this anomaly relatively unscathed, but were granted with their odd abilities (shadow form, more strength, etc).
However, no one knows what caused the space-time anomaly to occur or why the all of the Shadowbugs happened to encounter it and survive. Records indicate that there was nothing in that part of space that could have caused the anomaly to happen, almost as if the anomaly came out of nowhere. After several years, the anomaly seemed to instantly vanish as if it were never there. Newer readings from that area came up as normal, as if it was business as usual.
Much speculation is had regarding this matter, with no clear answer from anyone as to who or what caused the anomaly to appear. However, at around the time the anomaly occurred, some individuals of races with ties to long-forgotten civilizations and alien occultism made claims that were dismissed. Though seemingly not plausible, one could make a roundabout connection between this and the anomaly that affected the Shadowbugs. They were along the lines of:
"...Two forces beyond our comprehension are locked in a vicious battle outside the Multiverse. Forces that are so incredibly powerful that they caused a ripple effect that either destroyed or distorted the properties of many universes, even from that incalculable distance."
Phew, that was a lot to write. There's a reason why I am typing all this. It's meant to be a way to sort of tie all of my concepts together and have some modicum of explanation as to why oddities like Shadowbugs are a thing in my AUs.
...I'm going to end up writing the IZ Edition of the Lovecraftian mythos, aren't I? XD