Bucky Barnes

James Buchanan "Bucky" Barnes is the sidekick of Captain America, when Bucky accidently walked into Steve's changing room he became Bucky. Bucky was also Captain America when he thinks Steve Rogers is dead. Bucky appeared in Captain America: The First Avenger as a young private, Captain America tried to save him but he fell to his death.

Bucky is similar to Batman's sidekick Robin.