Hydra (often capitalized as HYDRA) is a fictional terrorist organization appearing in American comic books published by Marvel Comics. Its name alludes to the mythical Lernaean Hydra, as does its motto: "If a head is cut off, two more shall take its place," proclaiming the group's resilience and growing strength in the face of resistance. Originally a Nazi organization led by the Red Skull during World War II, Hydra is taken over and turned into a neo-Nazi international crime syndicate by Baron Wolfgang von Strucker. Hydra agents often wear distinctive green garb featuring a serpent motif. Hydra's plans for world domination are regularly foiled by Marvel Universe superheroes and the intelligence organization S.H.I.E.L.D. Hydra has appeared in various media adaptations, including films, television series, and video games. It plays a major role in the Marvel Cinematic Universe.
