Originally Posted by NineThePuma
Zerg wouldn't work as is, but you could steal a lot of the fluff and set them up as a number of races pulling from Giants and Goblinoids.
Protoss without Psionics aren't protoss. You could do a magical version, but they end up being telepathic anyway.
Alternatively, you could make the race modular.
What I mean by this is have a whole host of Templates, feats, and grafts that can be applied to a very basic base Race(That even more basic that the PHB races).
For instance, Zerg Base Race:
+2 Con, -2 Intelligence
(Ex): All zerg characters can communicate with one another telepathically. They do not requires the use of their mouths nor hand gestures in order to convey complex messages to one another.
And then you have to choose, say, a specific Zerg Template on top of that(Such as Zergling, Ultralisk, etc). This template would have it's own unique abilities and modifiers, with a level adjustment ranging from 0 (Zergling) to say +2 or so (Ultralisk, mutalisk, etc).
Add some Zerg specific feats and grafts and you have yourself a race.