Go behind the scenes of the new GI Joe movie "Retaliation" to see how they brought the classic HISS tank to life. The Cobra High Speed Sentry (H.I.S.S.) Tank has been the dominant tank used by Cobra forces since the organization's inception. The H.I.S.S. has been upgraded and remodeled over time, but all variants share a similar general design, featuring dorsal mounted cannons.