at first I thought the big daddies were the mutated dogs of the little sisters, (unquestioning loyalty, dog-like howling, limited intelligence.) what were they really? I thought it would be more dramatic and scary if they were some dog creature formed in the shape of a man but with limited brain capacity. or if they were formerly pets of the little sisters. what were they?
Big Daddies are (or were) humans. They were captured humans (possibly Fontaine's men, I don't remember) who underwent forced mutation and mental manipulation as well as having their skin and organs grafted on their suits (eww!).
Not at all dog like, except of course in their loyalty to the Little Sisters. Always felt sorry for them, though they aren't any longer able to think for themselves.
The Big Sister in BioShock 2 is apparently a Little Sister that grew up.
$ sudo make CHEEZEBURGER --mayo -off system made you CHEEZEBURGER but ated it :-(
That makes sense since at the end of the gameplay trailer the Little Sister said, "Mr. B, Big Sister doesn't want to play with you anymore." Or something like that, very eerie.
I'm interested into how all of this will turn out.