“ Somewhere along the line, someone very powerful lost their marbles. Literally. Possessing a marble allows incredible clarity of thought about a particular related subject.”
“ Feral teenagers:
Teenagers who run away from home to live in the wilderness may become feral. As they become more and more feral, they gain some supernatural powers (a la Peter Pan - ability to fly, things they imagine come true - possibly quite powerful), but at the expense of their humanity and ability to speak, comprehend complex subjects, etc. Maybe they have a leader: the most feral of them all.
A regression into a fantasy childlike state.”
“ Inside a mad scientists laboratory the PCs find a short creature with smooth, oily and whale like skin. The head is faceless and smooth also. But hundreds of white eyes on the PCs from the fat belly of this creature. The PCs are about to kill it as it speaks to them in a feeble but intelligent voice, asking them to pour the contents of a green vial on it. Will they do so? And if so, what will happen?”