Big Bird is a Muppet character designed by Jim Henson and built by Kermit Love for the long-running childrens television show Sesame Street. He is an eight-foot two-inch tall bright yellow anthropomorphic bird who lives on Sesame Street. Big Birds appearance has changed over the years, as has his personality. He originally had very few feathers on top of his head; his body feathers were also more shaggy and unkempt, and his body was not as rounded and full as it is now. His personality was more dopey and "bird-brained" than it later became. He gradually got more feathers on top, giving his head a more rounded appearance, and developed a blaze-like crest of lighter yellow feathers above his eyes.

Despite being a bird, there is no clear consensus on what kind of bird Big Bird is. On a 1976 Hollywood Squares appearance, Big Bird identified himself as a lark. When he visited Mr. Rogers’ Neighborhood in 1981, he claimed to be a golden condor. Sometimes he has been referred to as a canary, but he is much larger than any real-life canary. Mike Dickison, a zoologist, speculated that Big Bird is a special kind of bird that was a sort of evolution of the whooping crane. However, there is still speculation surrounding this fact, and no definitive answer has been given.