HYDRA is a fictional terrorist organization in the Marvel Universe.
Despite the name's capitalization per Marvel's official spelling , the name is not an acronym but rather a reference to the mythical Lernaean Hydra. The organization's motto references the myth of the Hydra, proclaiming that if a head is cut off, two more will take its place, proclaiming their resilience and growing strength in the face of resistance. HYDRA agents often wear distinctive green garb featuring a serpent motif.
The organization first appeared in Strange Tales #135. In its original continuity, it was headed by nondescript businessman Arnold Brown, who was killed as S.H.I.E.L.D. apparently crushed the organization. It soon returned, however, headed by Baron Wolfgang von Strucker, with the support of the Nazi Red Skull; HYDRA's changing origin was one of Marvel's earliest retcons. After its initial defeat, several of its branches, such as its scientific branch A.I.M. (Advanced Idea Mechanics), became independent. Other factions included THEM and the Secret Empire.
HYDRA is a criminal organization dedicated to the achievement of world domination through terrorist and subversive activities on various fronts, resulting in a fascist New World Order. Its extent of operations is worldwide, always attempting to elude the ongoing counter-espionage operations by S.H.I.E.L.D. HYDRA is funded by Baron Strucker's personal fortune, based on his recovered hoard of Nazi plunder from World War II, and funds established by the original leaders of the Japanese secret society that became HYDRA.
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