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The Morpho
According to the Minion Guide, the Morpho butterfly's scales were an ingredient of a powerful poison that effectively shut down the ability to recharge the mana of the Mages (like a perceptual Astral Fire), which would be a great boon to those seeking to defeat their opponents of magical power. The butterflies are on Hydaelyn's Endangered Species list as a result, but the interesting thing is that they (butterflies) were found on Amdapor Hard Mode and were seen as Mutant Warmoras (made explicit with Achamoth as well as the fact that butterflies were called "Magicked Warmoura"). It has me wondering if they were not Native to the shroud at all but were "imported" there by Mhach as a biological weapon of sorts.
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Mimicry exists as well, and butterflies happen to be a prime example for it.
Its very possible the Magiced Warmoura are mimics, perhaps through magic; Warmoura that were warped either to try to replace the dwindling Morpho population or fool outsiders (or the natives, who knows who magiced them) into thinking that they were just really big Morpho (but, without the magic-blocking scales).
As to whether they're native to the Shroud...its basically impossible to say. Especially since both Mhach and Amdapor (probably Nym too) hunted them.
My best guess would be they're native to somewhere between the three, maybe Coerthas or Dravania or south(eastern) Mor Dhona