Bucky Barnes, also known as the Winter Soldier, is a fictional character in the Marvel Comics universe. He first appeared in 1941 as the sidekick of Captain America. Bucky is a skilled fighter and marksman, originally portrayed as a young soldier during World War II. After a presumed death, Bucky was found and brainwashed by the Soviet Union, becoming the Winter Soldier, a covert assassin. Over time, he struggles with his past and seeks redemption, eventually taking on the mantle of Captain America in the comics. Bucky is known for his complex character arc and deep connections to other heroes.