Monstrology creatures that could be extracted, but can't
The broad categories for Monstrology make a fascinating and diverse array of creatures that are able to be extracted. However, there are also a select few creatures across the Spiral that cannot be extracted, despite their appearance suggesting that they could theoretically fall into one or more categories. Here are a few that I have noticed:
1: The Terror, a Sun-school boss in the dungeon connecting Outer and Inner Athanor, appears as if it could be collected with Extract Wyrm. However, it is currently unable to be extracted.
2: Melanj and the Sand Wurm Larvae in Caterwaul Canyons in Mirage appear as if they could be collected with Extract Insect.
3: The Earworms in the Aero Plains in Empyrea, as well as the Brainworm and Hookworm, could also theoretically be extracted with Insect.
4: The Bronze Holpite and Praetorian Guard in Aquila are Eagles fashioned out of bronze, suggesting that they could be extracted with either Colossus or Golem.
Re: Monstrology creatures that could be extracted, but can't
. The Vine Monsters, creatures in the "To Avalon" dungeon in the Wizard City Catacombs, are theoretically extractable with Treant. However, this is not the case.
. Ever since it came out, Monstrologists have wanted the Shadow Weavers to be extractable with Insect. Currently, the only extractable Shadow Weaver is the Arachna Soldier in Empyrea's Husk (Which is extracted with... Spider?). This should be expanded to include every Shadow Weaver in the game.
. Baba Yaga's Statue minions could theoretically be extracted with either Golem or Colossus. Currently, only the Wyrm Statue is extractable, and that's because it falls into the Wyrm category.
. The Pox creatures in the Spiral, especially the Corpse Lanturn in Avalon, could reasonably fall into either the Undead or Imp categories. (I'm not sure which, but Imp could do with more creatures.)
Re: Monstrology creatures that could be extracted, but can't
The Shriekers in Newgate are class undead, but I am unable to extract them using undead, or any other type I've tried. I only get the 'wrong monster type' message.
Also I was unable to extract Baba Yaga's wyrm statue using collect wyrm.