What is the Hurley Bird

A large bird nicknamed the "Hurley Bird" has made two appearances in Lost. According to the producers' May 4th, 2007 podcast, it has a 16 foot wingspan and cannot be found living in Los Angeles.
While in the Dark Territory, Hurley saw a huge bird, convincing him that whoever came up with the name Dark Territory was "a genius." ("Exodus, Part 2")
Later, traversing through the jungle, Michael, Jack, Kate, Sawyer and Hurley had a seemingly giant green bird swoop down over their heads that screeches what sounds like, "Hurley." Hurley asked if the bird screeched his name and Sawyer replies, "Yeah, it did. Right before it crapped gold." Michael attempted to shoot at the bird, revealing that the gun Jack had given him was unloaded. ("Live Together, Die Alone")
According to the DVD subtitles, the bird screeches say "Hurley" in both appearances.

Source: Lostpedia