Hydra is a fictional terrorist organization appearing in American comic books published by Marvel Comics. The name "Hydra" is an allusion to the mythical Lernaean Hydra.[2] The organization's motto references the myth of the Hydra, stating that "If a head is cut off, two more shall 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.