Doctor Who 2008, episode 03

Lesson of the day: Slavery is bad. Who'd have thunk?
Again, this is a neat, very pulpy episode, again decently paced and entertaining enough. The worldbuilding could have used a little more (or any) thought though. I can't be the only one to think that the survivability of a species whose members carry their second brains in their hands is low to the point of no-existence. And - nice as they may look - the Ood's whole physical conception doesn't make any sense (even for the Doctorverse). They're completely humanoid, just with the face of Cthulhu and an outside brain that permanently blocks the usage of one of their hands!? What the fuck?