Sometime in the future, when they will probably be third level, the PCs will return to a castle which sits in a mountainous area on a small hill overlooking a village. They will rest there, chat with the people who live there (they've befriended the lord of the castle in a previous adventure), and generally make themselves at home there.
Their stay won't be as peaceful as they are expecting, of course. The wizard who lives in the castle has recently acquired something very unusual from adventurers - a large, green egg. Unknown to him, it contains a half-fiendish wyrmling green dragon.
And it is about to hatch.
Basically, I want to rip off the Aliens
from the movies, and I figured that a wyrmling half-fiendish green dragon should come pretty close to the description of "acid-spitting killing machine". Of course, to properly install the sense of claustrophobia and paranoia, I need to come up with ways of allowing this creature to move around relatively freely without detection. It needs places to hide, and cramped passages where Medium-sized creatures will have trouble fitting in. I also need some imaginatively shocking scenes where the PCs can realize just how dangerous this monster is by discovering the remains of its victim. And I also need some reasons for why it might seem like a good idea for PCs and NPCs to split up...
Any suggestions are welcome!
(Posted to dnd3e