Ducky

From BioShock Wiki

The Splicer model "Ducky" first appears in Neptune's Bounty. He is dressed in the full waterproofs and peaked cap of an early 20th-century policeman. Based on his rantings, he appears to have a large degree of paranoia (which is not to suggest that the other Splicers are mentally sane). His dialog suggests that he is a security officer, answering to a "Mr. Coswell". The possible corpse of Sullivan is a Ducky model.