Quote Originally Posted by Janusz
Well, I'm not sure at all. Hollow's can get stronger ofcourse, see the Grand Fisher dude. But seeing how the Grand Fisher was relatively intelligent, and a Menos is pretty stupid, I don't think a normal hollow would somehow evolve into a giant, stupid, more powerful hollow.
I thought they said that Menos are actually made up of many Hollows merged into one being.

Also, I think only the level one Menos, the Gillians, are mindless. The Adjuchas and the Vasto Lords are shown to be intellegent.