He is first seen when Chicken Little, who says the sky is falling, leads the townspeople to the Oaky Oak's tree where the acorn hits him in the head, claiming that it was the piece of the sky. Buck comes into the scene and tell them that it was a big misunderstanding, causing the town to scoffs off Chicken Little's delusions. One year after the acorn incident which the movie about Chicken Little is in the making, Buck drives Chicken Little to the bus stop, telling him to "lay low."
After the gym incident, Buck is in the principal's office where the principal tells him about the "bad things" Chicken Little has done. After learning that Buck was a high school baseball star, Chicken Little tells Buck that he wants to join baseball.
At the Championship Baseball game, Buck watches Chicken Little play. After two misses of hitting the ball, Chicken Little finally hits the ball and runs laps to the final lap before the players hits him with the ball. Everyone thought Chicken Little has lost until the pile of dirt gets cleaned off, revealing that Chicken Little has his foot touch the tip of the base, declaring him the winner. This makes Buck feel so proud of him.
After Chicken Little discovers a hexagonal object belonging to a UFO that can camouflage everything, Buck is seen along with citizens following Chicken Little to the baseball field where the UFO was located before it disappears. Chicken Little tries to explain the town about the UFO, but they think that he is back to his delusional self again. This makes an embarrassed Buck refuses to believe Chicken Little.
The next day, when a thousands of aliens in UFOs starts "terrorizing" Oaky Oaks, Chicken Little explains to Buck that aliens are actually searching for a young orange alien named Kirby, but Buck doesn't quite understand. Frustrated of his disbeliefs, Chicken Little leaves Buck to find Kirby.
At the movie theater, after Chicken Little finally tells him about how he is never supportive of him, (except at the baseball game), Buck feels guilty and apologizes to Chicken Little for not being good of a father that he is. Later, Chicken Little tells Buck to take Kirby to on top of Oaky Oaks' town hall where the UFO of Kirby's parents are seen above in order to reunite them. While so, the aliens chases after Chicken Little, Buck and Kirby, until Abby, Runt and Fish save them in a firefighter's truck just so they can take them to town hall. After finally made it there, the three finds the elevator is unfortunately out of order, so instead they take the stairs. When made it to the top of town hall, Buck gets stuck in the doorway due to his fatness so Chicken Little gets to do this on his own, which Buck finally trusts his son, saying "I do, son." When Chicken Little shows Kirby to his parents that he wasn't hurt, the aliens are coming towards Buck. Then, Buck finally smashes out of the doorway to get to the top, where he fights off the aliens to protect Chicken Little. Chicken Little, Buck and Kirby got vaporized and sent to the void where they were encountered by Kirby's father, Melvin, who accuses them for kidnapping his son. Buck tries to explain that he left Kirby behind by accident (albeit calling it "bad parenting"), but Melvin did not believe them. After Chicken Little and Buck let Kirby go, Melvin intimidating the two with weapons, but Kirby stops him and explains to him that they were telling the truth. Then, the aliens restore everything they vaporized from the town
After the aliens leave, Chicken Little, Buck and his friends, along with the citizens of Oakey Oaks, watch a movie about him, Abby, Runt, and Fish fighting off aliens to save the Earth.
Buck is seen dancing along with the characters in the credits while "Don't Go Breaking my Heart" plays.
Buck is a caring, kind, thoughtful and well-meaning person, but struggling to understand and listen to his son, Chicken Little.
He tends to be something of an anxious, fearful pessimist and somewhat doubtful, but soon becomes more optimistic and confident by the end of the film.
Buck can also sometimes be a nervous wreck.
Despite his insecurities, he is also a good fighter, such as when he beat up the aliens.
Buck is a tall, overweight rooster with orange feathers, a red comb, and dark red bushy eyebrows.
He usually wears a cream, plaid dress shirt, along with a dark brown neck tie and large brown pants. His sleeves are also rolled up.
Before Garry Marshall was cast as Buck Cluck, Charlie Sheen, Christian Slater, Joseph D. Reitman, Peter Falk, Dennis Hopper and Mick Jagger was originally considered for the role.
There is a constroversy with people's hatred to Buck for his incompetence and negligence as a parent, considering him the anti-hero or villain. Despite his embarrassment to Chicken Little's ridiculing, he tries his best to support him.
The Mysterious Mr. Enter (or Mr. Enter) is the best example of it.