Songbird

Songbird is a 30-foot winged creature that is feared by the citizens of Columbia, and is Elizabeth's guardian. It is an influential character in BioShock Infinite.

History
When Elizabeth was imprisoned in Columbia for fifteen years, a creature, simply called Songbird, was created for the sole purpose of keeping her in prison and became the most feared creature in all of Columbia. During that time, Songbird was the child's only company. Although Elizabeth was held captive by Songbird, the creature had been her caretaker and protector. Eventually, she grew to love him as her only friend. When she had escaped, the creature was intent to bring her back, even if it meant destroying anyone and anything near Elizabeth, including Booker DeWitt. Although he is a threat to the latter, Elizabeth still loves him enough to avoid conflict at all costs: if Booker decides to attack Songbird, his relationship with her will deteriorate.

Trivia

 * Originally, when first revealed in October 2010's issue of Game Informer, Songbird was referred to as simply "Him". The name didn't change until May 23, 2011, when interviews and a preview of the gameplay demo had finally revealed the name as Songbird.
 * Songbird bears a strong resemblance to the Big Daddies in Rapture: its eyes are reminiscent of portholes, and produce a yellow light which turns red when Him becomes hostile. In addition, the sound made by Songbird as he approaches DeWitt in an early gameplay demo is identical to that of a Big Daddy roar. It can also be noted that he is tasked with the protection of Elizabeth, a relationship not unlike the one between the Big Daddies and Little Sisters in Rapture. Additionally, Songbird is able to cause damage to the world around him, even toppling a water tower on one occasion. Unlike Big Daddies, though, it is not mass-produced, and resembles a giant gargoyle rather than a man in a diving suit. Songbird also does not use weapons to obtain its means, only using its tremendous size in its endeavors. Songbird is also very fast, even in a passive mood, compared to the Big Daddy.