Just out of curiosity, and I'm not sure if this has been discussed before, but does anyone have any theories on what affects the kind of troll an infected human becomes? For example, the Notoros are implied to be former children, yet they've shown an understanding of guns, problem solving abilities (catapulting one at a window, even though it didn't work), and can speak. Plus, I'm curious about what caused them to grow those thick hides that allows them to withstand more light than other trolls.
Compare them to some of the other formerly human trolls the team has met, and they look quite different, like leaf troll (I think that's what it was called) or the one that was clinging to the ceiling in that hospital way back. Leaf troll seemed somewhat intelligent, burrowing under the snow, but couldn't really speak, and the ceiling troll acted more like an animal.
The transformations' effects seemed random at first, but now we're seeing specific types, which I find pretty interesting.