James Buchanan "Bucky" Barnes is the protégé and childhood friend of Captain America, and a member of an elite special unit of Allied soldiers formed in World War II known as the Howling Commandos. He was assumed dead after falling off of Zola's Train.
However, he resurfaces decades later as the Winter Soldier, a brainwashed, mega-enhanced Super-Soldier doing dirty work for a mysterious organization. The hardened Winter Soldier has no memories of his former identity and that suits him just fine — he is simply a killing machine.
Current Version:
White Wolf
Former Version:
Bucky
The Winter Soldier (HYDRA)
The Winter Soldier (Freed)