Songbird is a mechanical bird, created by Fink Industries. It was made for the sole purpose of protecting Elizabeth. Although as she mentions, he is more of her captor, that her protector. Songbird is summoned by a musical flute, called the Whistler. The Songbird is renowned for it's ability to reduce huge buildings to ruble, and is a worthy adversary of Booker DeWitt. Songbird was apparently inspired by a Big Daddy, seen in a Tear by Fink. Songbird was designed for high pressure environments, the low pressure environments such as water, are deadly to it. While hostile to the likes of Booker, Songbird can be tamed by Elizabeth, or anyone able to use The Whistler.