1, Hydra is a super villain organization under the American Marvel Comics, which made its debut in theNo. 135 issue of Strange Tales from a Lonely Studio (1965 August). Its origin is quite early, when a powerful alien hive appeared on the earth, which was sent to a distant planet because of its powerful ability. Its symbol is a skull and a snake's foot below.

2. The slogan of Hydra is "Cut off one head, and then grow two heads to replace it", which is consistent with the mythical image of Hydra and realized through its endless mixed soldiers. In modern times, the branch of Nazi hydra is generally considered as the hydra organization. During World War II, it belonged to Nazi Germany (later defected to the Nazis), and the Nazi Hydra was only founded by the Red Skull following the concept of Hydra in previous dynasties, not an orthodox Hydra.

3. The Nazi Hydra killed Tony Stark's father howard stark, but it was not destroyed. After the fall of Nazi regime, Hydra infiltrated SHIELD, created panic and chaos under the banner of SHIELD, and profited from the war. Later, it was exposed because of the overthrow of SHIELD, but it forced SHIELD to hide. The orthodox hydra organization was the main source of funds for the Nazi hydra after he left the Nazis.