Amongst the Big Daddy concept art in the free Bioshock art book I've mentioned, is this Big Daddy doll. What a great craft project, it looks like you'd need:
-doll wearing dress shoes
-5 mismatched buttons
UPDATE: Here's the Big Daddy toy featured on the Bioshock 2 teaser site:
Looks like the head is a baseball with pushpins shoved in, and the arms are rope.
*Previously: Day of the Dead geisha doll.
*Buy Bioshock toys at eBay.