Its name comes from the mythological Hydra, and their motto is the metaphor "cut a head and two will take its place", proclaiming the organization's resilience to foes. They would usually begin cheering out "Hail HYDRA!" upon hearing their motto.
Though HYDRA had long since been disbanded, their weapons and technology still existed. What was left was kept by S.H.I.E.L.D. for their program "Phase 2," which involved reactivating the HYDRA weapons with the Tesseract for use against super-powered or other-worldly forces. Steve Rogers discovered several cases of HYDRA weapons aboard the S.H.I.E.L.D. Helicarrier.
Rogers also mentioned during a meeting that Bruce Banner should study Loki's Staff while hunting for the Tesseract, as it functioned similarly to HYDRA's weapons.
Agent Phil Coulson's team travels to Peru to investigate an "0-8-4", an unknown object of concern to S.H.I.E.L.D. The object is an anachronistically advanced metal device in an ancient pyramid. Coulson's team eventually discovers that it is a Tesseract energy-powered weapon designed by surviving Nazi/HYDRA scientists who escaped Allied justice after WWII and were recruited by Peru. A team of Peruvian military police attempts to kill the team in order to retrieve the device, but Coulson's ingenious team members foil them. In the end, the 0-8-4 is deemed too dangerous to be allowed to exist, and it blasted off on a rocket into the Sun.
HYDRA's level of technology is as highly advanced as that of any on Earth, based in part on technology of the alien Gnobians discovered by Baron von Strucker in 1944. HYDRA uses various advanced experimental vehicles and devices in its activities, and various conventional military vehicles, seacraft, aircraft, pistols and standard concussive force blasters, and conventional communications equipment.
HYDRA personnel are issued cowled jumpsuits, which have included a number of designs over the years. Originally, the jumpsuits were green with a yellow H design, and later incorporated a red and brown color scheme, but in time were changed back to green with a serpent motif.
- Red Skull (Leader)
- Arnim Zola
- Baron Von Strucker (Second Commander)
- Baron Zemo (Second Commander)
- D.R.E.A.D.N.A.U.G.H.T.S. (robots)
- Madame Hydra
- The name of the organization is named after the Greek mythogical monster the Hydra.
- Its emblem seems to resemble the SPECTRE octopus, the symbol of the antagonists in the James Bond series; this could be the source of inspiratio for the HYDRA emblem.